390_USB USB from Scratch
V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Objective O
When you walk out of this class, you will − Understand the basics of USB, and how it can be used in an embedded application − Be familiar with Microchip’s MCUs, development boards, and USB software framework. − Be able to create a simple PC application that exchanges data with a USB device
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Agenda O
Part 1: −Introduction to Full-Speed USB
O
Part 2: −Introduction to Microchip MCHPFSUSB Firmware Solutions and Hand’s-on with CDC Class RS-232 Replacement APIs
O
Part 3:
−Using the Microchip General Purpose USB Windows® Driver and Custom Class Device Firmware
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Part 1. Introduction to Full-Speed USB
V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Objectives O O
O O
Understand how USB can be useful in an embedded system Learn about fundamental USB architecture, protocol and programmer’s model Be aware of the factors important in designing a USB application Identify key USB capabilities in PIC18 USB MCUs
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Agenda O O
Brief history of USB & USB-IF USB Fundamentals - The serious & important stuff − − − − − − − − − −
O O
Basics/Speeds Architecture/Programmer’s Model Physical Connection USB Transactions USB Transfers Device Classes Enumeration Descriptors Power Planning VID/PID & USB Compliance
PIC18F USB Microcontrollers Microchip Demo/Development Solutions
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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A little history... O
USB was co-developed by a group of companies…. − − − − −
O O
Compaq Intel Microsoft NEC …who wanted to make it much easier to add/remove peripheral devices from PCs
1998 - USB 1.1 2000 - USB 2.0
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Universal Serial Bus Extend the functionality of your computer! Data Analysis, Data Logging, Firmware Updates, Diagnostics, Embedded Applications!
• • • • •
Auto detection & configuration (Plug&Play) Easy expansion using hubs Bus power Data CRC protected, bad packets resent. Three speeds: Low- 1.5, Full- 12, High- 480 Megabits / second
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
Serial Parallel PS/2
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USB Basics O
USB is a “Single Master + Multiple Slaves” polled bus USB Host Controller (Master) and Root Hub
Mouse
Printer
Speaker
Start Of Frame SOF
Int EP1
Iso EP1
Iso EP1
1 ms © 2008 Microchip Technology Incorporated. All Rights Reserved.
SOF
Int EP1
Iso EP1
Iso EP1
1 ms 390_USB v1.10
SOF
Int EP1
Iso EP1
Bulk Bulk EP2 EP2
1 ms Slide
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Buses & Speeds Comparison 1394-Fire Wire
Does not have to support High-Speed to be USB 2.0 Compliant
Ethernet WiFi (b/g)
USB 2.0 LS-USB 1.5 Mb/s
HS-USB 480 Mb/s
USB 1.1
CAN Serial Port 500 Kb/s
FS-USB 12 Mb/s
Parallel Port 1 Mb/s
© 2008 Microchip Technology Incorporated. All Rights Reserved.
1.5 Mb/s
12 Mb/s 390_USB v1.10
100 Mb/s 480 Mb/s 1 Gb Slide
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Biggest Myth O
MYTH: A Low-Speed USB peripheral can transfer application data up to 187.5 KB/s
O
(1.5 Mbps)
FACT: Impossible, because of a USB specification restriction:
− 8 byte data transfer every 10 ms − = 800 Bytes/second only
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Next Biggest Myth O
MYTH: A Full-Speed USB peripheral can transfer data up to 1.5 MB/s
O
(12 Mb/s)
FACT: Impossible, 1.5 MB/s is the total bus bandwidth − − − −
Must be shared among peripherals Protocol overhead Protocol restrictions Realistic raw data throughput to a single peripheral is ~1.0 MB/s − Only 64KB/s in some cases © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Key: Speed Capability All PIC18 USB Devices Full-Speed & Low-Speed
PIC16C7X5 Low-Speed Only
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Physical Bus Topology USB Host Controller & Root Hub
Host (Tier 1)
Tier 2
Keyboard
Tier 3
Speaker
Hub
Logic Analyzer
Hub
Tier 4
Hub
Tier 5
Hub
Tier 6
Hub
Tier 7
Data Logger
Up to 126 peripherals... © 2008 Microchip Technology Incorporated. All Rights Reserved.
Hub: Max Chaining = 5
PIC18 USB devices are designed to be peripherals! Hub
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Logical Bus Topology O O
Not a tiered-star! Host software communicates to each “logical” device as if it were directly connected to the root hub Host Logical Device
Logical Device Logical Device
Logical Device Logical Device © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
Logical Device
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Accessing PC Peripherals O O
Old Way PC Peripherals: − Memory-mapped into the x86 I/O address space − Assigned a specific IRQ line − Assigned a specific DMA channel
O
O O
− Mapped into a virtual 127 device address space − Does not use any PC I/O, IRQ or DMA resources O
Accessed directly (ISA, PCI, PCMCIA)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
USB Way PC Peripherals:
390_USB v1.10
Accessed indirectly using the programming interface provided by the device driver Slide
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Sending/Receiving on the PC O O
Only High Level Access Four Basic Function Types: − − − −
MPUSBOpen(VID, PID, Endpoint, Direction) MPUSBRead(Pointer, Size, Timeout) MPUSBWrite(Pointer, Size, Timeout) MPUSBClose(Handle)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Sending/Receiving on the Device O O
Only high level access Example: CDC Class RS-232 Emulation
void void void void byte byte
putrsUSBUSART(const rom char *data); putsUSBUSART(char *data); mUSBUSARTTxRom(rom byte *pData, byte len); mUSBUSARTTxRam(byte *pData, byte len); getsUSBUSART(char *buffer, byte len); mCDCGetRxLength(void);
You are not directly reading/writing to the peripheral SFRs anymore! © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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USB Device Framework Peripheral Device
Non USB Format
USB Device Driver
N - Driver Specific Pipes (Ep1..)
Non USB Format
USB System Software
Physical Device
Device Specific Comm
2-Default Control Pipes (Ep0_OUT/IN)
Logical Device
USB Data Frames
USB Adapter/Controller
USB Device Bus Interface Layer Layer
Bus Interface USB Device Layer Layer
Host System User Code
Function Layer
Function Layer
- Software View of Hardware -
USB Data Frames
Cable
Bus Interface
Physical Communication Path Logical Communication Path (“Pipe”) © 2008 Microchip Technology Incorporated. All Rights Reserved.
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The “Logical” USB Device Device (Manufacturer: Microchip Technology) (Product: Mouse in a Circle Demo) (VID_PID: 04d8_0000)
Configuration (Active)
Interface (Mouse) USB Device-Specific Pipe(s) (HID)
Endpoint 1 (Interrupt - IN)
Analog/Digital I/O
MCHPFSUSB HID TX/RX Functions
Endpoint 1 (Interrupt - OUT)
USB System Software (default control pipes)
Endpoint 0 (Control - OUT)
Endpoint 0 (Control - IN)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
Logical settings are represented by a Device Descriptor Table, stored in the device…more on this later. Slide
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Physical Interface
O O
VBUS
VBUS
D+
D+
D-
D-
GND
GND
~ 5.0 V ~ 3.3 V
Half Duplex with NRZI Data Encoding Bus Power to each device: − − −
4.40 - 5.25 V Guaranteed 100 mA 500 mA maximum through negotiation
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
Must use external power if more is required
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USB Connectors “A” Plug USB Host
“B” FS, HS Peripheral
“mini-B” FS, HS Peripheral
“micro-B” Peripheral
LS, FS, HS Peripheral Hardwired or Custom Detachable
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Agenda O O
Brief history of USB & USB-IF USB Fundamentals - The serious & important stuff − − − − − − − − − −
O O
Basics/Speeds Architecture/Programmer’s Model Physical Connection USB Transactions USB Transfers Device Classes Enumeration Descriptors Power Planning VID/PID & USB Compliance
PIC18F USB Microcontrollers Microchip Demo/Development Solutions
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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How do the host and the device communicate?
Transactions… V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
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An Endpoint is a Buffer Data Bucket
OUT Transaction
IN Transaction
O
RAM Endpoint 1 IN
LED
Keystroke(s)
Maximum number of endpoints per device specified by USB specification: − −
O
RAM Endpoint 1 OUT
16 OUT endpoints + 16 IN endpoints = 32 endpoints PIC18F87J50, PIC18F4550 supports up to 32 endpoints
EP0 = Default Communication Pipe
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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USB Transaction USB Transaction Token Packet
SETUP and OUT token types inform the target device that the host wants to send data. IN token type informs the target device that the host wants to fetch data. © 2008 Microchip Technology Incorporated. All Rights Reserved.
Specifies: • Target device address • Endpoint number • Direction of the data transfer
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USB Transaction - IN USB Transaction IN Token Packet
Data Packet
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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USB Transaction - IN USB Transaction IN Token Packet
Data Packet
Handshake Packet
Acknowledge - ACK © 2008 Microchip Technology Incorporated. All Rights Reserved.
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IN Transaction ACK USB Traffic
USB PIC® MCU
USB Transaction IN Token Packet (to EP1 IN)
Data Packet
Serial Interface SIE Sends Data
Engine
RAM Endpoint 1 IN
0
SFR EP1 IN BD (UOWN, Length, Pointer)
Update BD
390_USB v1.10
= WN Keystrokes
UO s t e S
Handshake Packet
© 2008 Microchip Technology Incorporated. All Rights Reserved.
SFR EP1 OUT BD If U RAM (UOWN, Length, OW Endpoint N = 1 OUT Pointer) 1
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IN Transaction NAK USB Traffic
USB PIC® MCU
USB Transaction IN Token Packet (to EP1 IN)
Serial Interface
Handshake Packet
© 2008 Microchip Technology Incorporated. All Rights Reserved.
Engine
SFR EP1 OUT BD If U RAM (UOWN, Length, OW Endpoint N = 1 OUT Pointer) 0 RAM Endpoint 1 IN
SFR EP1 IN BD (UOWN, Length, Pointer)
SIE Sends NAK
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OUT/SETUP Transaction ACK USB Traffic
USB PIC® MCU
USB Transaction OUT/SETUP Token Packet (to EP1 OUT)
Serial Interface
Data Packet Handshake Packet
If U
SIE Deposits Data
Engine SIE Sends ACK
© 2008 Microchip Technology Incorporated. All Rights Reserved.
OW N=
1
SFR EP1 OUT BD RAM (UOWN, Length, Endpoint 1 OUT Pointer)
=0 N OW SFR EP1 IN BD U , RAM h t g (UOWN, Length, enEndpoint 1 IN L s Pointer) Set
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OUT/SETUP Transaction NAK USB Traffic
USB PIC® MCU
USB Transaction OUT/SETUP Token Packet (to EP1 OUT)
Serial Interface
Data Packet
Engine D
SI E
Handshake Packet
isc ar ds Da SIE Sends NAK ta
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
If U
OW N=
0
SFR EP1 OUT BD RAM (UOWN, Length, Endpoint 1 OUT Pointer) RAM Endpoint 1 IN
SFR EP1 IN BD (UOWN, Length, Pointer)
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A Transaction in Action
- Beagle12 Capturing READ_POT -
Refer to Appendix A in Handout for the complete PDFSUSB Command/Response Reference
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Key: Token Types SETUP
OUT
IN
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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How do the host and device communicate?
Transfers… V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Transfers Vs. Transactions MPUSBWrite(EP7, Pointer, Size = 129, Timeout)
Transfer Transaction 1
Key: OUT Token Packet
64 Byte Payload
Data Packet
Transaction 2
ACK Handshake Packet
64 Byte Payload
Transaction 3 Transfer: Group of related transactions.
1 Byte Payload
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Data Transfer Types Transfer/ Endpoint Type
Polling Interval
Priority
USB FS.Max. # Data Bytes/Frame/Endpoint (# transactions per frame)*
Data Integrity
Interrupt
Fixed, Periodic
High
64 (1 x 64)
Yes
Isochronous
Fixed, Periodic
High
1023 (1 x 1023)
No
Bulk
Variable, Uses Low Free Bandwidth
1216 (19 x 64)
Yes
Control
Variable
832 (13 x 64)
Yes
Medium
*Assumes transfers use maximum packet sizes allowed per Ep type © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Interrupt Transfer Example MPUSBWrite(EP7, Pointer, Size = 129, Timeout) Traffic to other Endpoints or Idle
64
Transactions
1
64
Frame = 1ms © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Bulk Transfer Example MPUSBWrite(EP7, Pointer, Size = 129, Timeout) Transactions only occur if no higher priority traffic
Int.
Isoc.
Int.
64
64
Int.
1
Frame = 1 ms © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Theoretical Maximum Transfer Rate Per Endpoint 1400
1216
1200
1023
1000 KByte/s
832
800 600
Low Full
400 200 0
24
0.8
64
Control Interrupt
Bulk
Iso
Transfer Type © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Transfer Types - Examples
Mouse
Printer
Speaker
Control + Interrupt
Control + Bulk
Control + Isochronous
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Key: Transfer Types All PIC18 USB Devices Control, Interrupt, Bulk, Isochronous
PIC16C7X5 Control and Interrupt only
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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USB Device Classes Floppy Drive
Data Glove
Ethernet Adapter
Mouse External Hard Drive PICkit™ 2 Starter Kit Joystick
Mass Storage Device Class (MSD)
Modem
Communication Device Class (CDC)
Keyboard
ICD2 Custom Class (Vendor Class)
Human Interface Device Class (HID)
Many more classes…. © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Considerations When Using Standard Classes O
CDC (Virtual Com Port)
O
− Device communication protocol defined O
O
O
− Device communication protocol undefined
The PIC looks like a modem, or terminal connected to a serial port The PC Host application/PIC exchange ASCII strings (default) Call management packets sent in addition to the data packets −
O
O
PC application talks directly to the endpoint in the PIC The PC application/PIC exchange raw bytes
More on the USB CDC Device Class in Part 2
Lower data rate than custom class (80kByte/s vs 1MByte/s)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
Custom
390_USB v1.10
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Example – Using CDC Application Application
UART Driver
UART Driver
CDC Driver
UART Hardware
RS-232
USB Hardware
RS-232
USB
UART Hardware UART APIs Firmware Application
USB
USB Hardware
Microchip CDC RS-232 Emulation API
© 2008 Microchip Technology Incorporated. All Rights Reserved.
USB UART APIs
PIC18F4550
Firmware Application
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Agenda O O
Brief history of USB & USB-IF USB Fundamentals - The serious & important stuff − − − − − − − − − −
O O
Basics/Speeds Architecture/Programmer’s Model Physical Connection USB Transactions USB Transfers Device Classes Enumeration Descriptors Power Planning VID/PID & USB Compliance
PIC18F USB Microcontrollers Microchip Demo/Development Solutions
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Enumeration and the magic behind “Plug&Play” Auto-Detection & Auto-Configuration
V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Auto-Detection: Full-Speed Peripheral Device PIC18 USB Microcontroller VUSB 3.3 V
Full Speed Identification D+ line pull-up
1.5 kΩ±5% +5V D+
Transceiver
DGND
USB Connector
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Auto-Detection: Low-Speed Peripheral Device PIC18 USB Microcontroller VUSB 3.3 V
Low Speed Identification D- line pull-up
1.5 kΩ±5% +5V D+
Transceiver
DGND
USB Connector
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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On-chip Pull-up Resistors Peripheral Device
PIC18 USB Microcontroller VUSB 3.3 V On-chip pull-up resistors!
+5V
Controlled by UCFG & UCFG
D+
Transceiver
DGND
USB Connector
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Endpoint 0 and Enumeration O
See Chapter 9 in USB 2.0 Spec for more info. PIC18 USB Microcontroller Dual Port/Access RAM Endpoint 0 OUT (Control Data)
Control Transfers
Endpoint 0 IN (Control Data)
Descriptors
Other Endpoints
Bus Reset
Set Address
© 2008 Microchip Technology Incorporated. All Rights Reserved.
Get Descriptors 390_USB v1.10
Set Configuration
Device Ready Slide
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Descriptors Device
String 0 String 1
To other Configurations if any
String N
Configuration 1
To other Interfaces if any Interface 0
Endpoint O
Endpoint
Interface 1
Endpoint
Endpoint
Descriptors are typically stored in non-volatile/Flash memory
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Descriptors - Example Manu. String
Device
USB 2.0, VID = 0x04D8, PID = 0x0007, Num. Configurations, Strings?
Configuration 1
Configuration #1: Bus-Powered, Remote Wakeup, 500mA, Num. Interfaces
Interface 0
Interface #0: HID Class, Num. Endpoints
Endpoint
Endpoint 1 IN, Interrupt Transfer Type, 64-byte buffer, Poll every 3 ms
Microchip Prod. String
PICDEM USB Other String
Go USB!
Unicode Characters © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Viewing Descriptor Information - UVCView -
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Power Planning O O
Max USB suspend current is 0.5/2.5mA Don’t: Power from USB Cable
VDD 22µF
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Power Planning O O
Max USB suspend current is 0.5/2.5mA Do:
≤10µF
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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PIC® MCU: Detecting a USB Attachment
If the device is self-powered, you MUST use an I/O pin to detect a cable attachment. Must not pull up D+ or D- (and never source current on VBUS) until host drives VBUS high. © 2008 Microchip Technology Incorporated. All Rights Reserved.
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VID & PID O
Vendor ID (VID)
16-bit number
− Required to market your product − http://www.usb.org/developers/vendor/ − USD $2,000 − Technical & Legal trouble if not using your own VID O
Product ID (PID)
16-bit number
− Microchip’s Sub-licensing Program O
Every product line is required to have a unique combination of VID and PID
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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USB Compliance O
Compliance Testing − Must pass to use USB logo − USD ~$1,500
O
Ch9 and other USB Firmware − USB Protocol Analyzer − “USBCV” USB Command Verifier O
O
O O
Tests device for conformance to Ch9, Hub, HID , MSD and Video Class specifications www.usb.org/developers/tools/
Electrical Signal Quality Power Management
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Compliance Testing O
For USB Compliance: Independent Test Labs For Device ‘Sanity Check’: USB “Plugfest”
O
For USB Compliance Testing:
O
− Must submit a compliance checklist − www.usb.org/developers/compliance/peripheral_low/ − Download “Peripheral Checklist” − − − − O
TID: Test ID Use certified USB receptacle and cable for testing Know the TID of your components All USB PIC® MCUs have a TID number. Get it at www.microchip.com/usb
Probably a good idea to take a look at the checklist even before starting your design!
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Agenda O O
Brief history of USB & USB-IF USB Fundamentals - The serious & important stuff − − − − − − − − − −
O O
Basics/Speeds Architecture/Programmer’s Model Physical Connection USB Transactions USB Transfers Device Classes Enumeration Descriptors Power Planning VID/PID & USB Compliance
PIC18F USB Microcontrollers Microchip Demo/Development Solutions
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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PIC18 USB Flash Family NEW
PIC18F67J50 PIC18F67J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F87J50 PIC18F87J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F66J55 PIC18F66J55 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F86J55 PIC18F86J55 2.0 2.0 Full-Speed Full-Speed
96 KB 64 KB
32 KB
24 KB 16 KB
PIC18F14K50 PIC18F14K50 2.0 2.0 Full-Speed Full-Speed
8 KB
PIC18F13K50 PIC18F13K50 2.0 2.0 Full-Speed Full-Speed
20-Pin
PIC18F26J50 PIC18F26J50 2.0 2.0 Full-Speed Full-Speed
PIC18F46J50 PIC18F46J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F66J50 PIC18F66J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F86J50 PIC18F86J50 2.0 2.0 Full-Speed Full-Speed
PIC18F25J50 PIC18F25J50 2.0 2.0 Full-Speed Full-Speed
PIC18F45J50 PIC18F45J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F65J50 PIC18F65J50 2.0 2.0 Full-Speed Full-Speed
NEW
PIC18F85J50 PIC18F85J50 2.0 2.0 Full-Speed Full-Speed
PIC18F2550/3* PIC18F2550/3* 2.0 2.0 Full-Speed Full-Speed
PIC18F4550/3* PIC18F4550/3* 2.0 2.0 Full-Speed Full-Speed
PIC18F2455/8* PIC18F2455/8* 2.0 2.0 Full-Speed Full-Speed
PIC18F4455/8* PIC18F4455/8* 2.0 2.0 Full-Speed Full-Speed
PIC18F2450 PIC18F2450 2.0 2.0 Full-Speed Full-Speed
PIC18F4450 PIC18F4450 2.0 2.0 Full-Speed Full-Speed
* Denotes 12-bit ADC
NEW
Design Existing
28-Pin
© 2008 Microchip Technology Incorporated. All Rights Reserved.
40/44-Pin 390_USB v1.10
64-Pin
80-Pin Slide
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USB Module Peripheral Device Board 3.3 V Regulator Bus Pull-Up Resistors D+/D-
PIC18F4550
Transceiver
Data RAM USB RAM
SIE
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
Program Memory
Control Registers
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Serial Interface Engine SIE ... O Serializes and deserializes USB data O Encodes and decodes NRZI data D+/DO Handles bit stuffing O Checks CRC to validate data packet O Detects bus signaling events and notifies the CPU through interrupts O Handles USB transactions O Handles handshaking protocol © 2008 Microchip Technology Incorporated. All Rights Reserved.
PIC18 USB MCU
Transceiver
Data RAM USB RAM
SIE
390_USB v1.10
Program Memory
Control Registers
Slide
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System Clocks
Required for USB
© 2008 Microchip Technology Incorporated. All Rights Reserved.
SIE FS: 48 MHz LS: 6 MHz
CPU
390_USB v1.10
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Clock Configuration Example Peripheral Device Board PIC18F4550 20 MHz EC
Divide by 5
96 MHz PLL
Divide by 3
Divide by 2
Accept 4 MHz Input Only
SIE
PIC® MCU Core
32 MHz : 8 MIPs
SIE Clock = 48 MHz : Full-Speed Mode
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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Agenda O O
Brief history of USB & USB-IF USB Fundamentals - The serious & important stuff − − − − − − − − − −
O O
Basics/Speeds Architecture/Programmer’s Model Physical Connection USB Transactions USB Transfers Device Classes Enumeration Descriptors Power Planning VID/PID & USB Compliance
PIC18F USB Microcontrollers Microchip Demo/Development Solutions
© 2008 Microchip Technology Incorporated. All Rights Reserved.
390_USB v1.10
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PICDEM™ Full-Speed USB O O O O
PIC18F4550, 20 MHz xtal USB Port Serial Port PICtail™ Daughter Board Compatible
© 2008 Microchip Technology Incorporated. All Rights Reserved.
O O O
Power LED Indicators Potentiometer Temperature Sensor Part Number - DM163025
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PIC18F87J50 FS USB Plug-In Module (PIM) O O O O
PIC18F87J50, 12 MHz xtal USB Port, mini-B Linear Regulator 2 LEDs, 2 Pushbuttons
O O
O
Part Number – MA180021
Stand alone operation Operation with: HPC Explorer Demo Board ICSP™ Technology: 6-pin header HPC Explorer – DM183022
Part Number – AC164110 © 2008 Microchip Technology Incorporated. All Rights Reserved.
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PICtail™ Daughter Board for SD and MMC O O
Secure Digital Card Interface - using SPI AN1003: USB Mass Storage
Part Number – AC164122
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Microchip USB Firmware Characteristics O O O O
O
C18 Compatible MPLAB® IDE Project Centric Polling Scheme Cooperative Multi-Tasking (No Blocking Routines) Program Memory Usage − − − −
USB Enumeration (Chapter 9) HID CDC (RS-232 Emulation) USB Mass Storage
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Summary – Part 1 O
Basics/Architecture
− Up to 126 devices sharing bandwidth − Host is master
O
Host/Device Communication − Transactions − Transfers
O
Enumeration/Chapter 9 − Descriptors
O
Microchip Offerings: MCUs, Demo Boards, Firmware, Custom Driver
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Part 2.
Introduction to Microchip MCHPFSUSB Firmware Solutions and Hand’s-on with CDC Class RS-232 Replacement APIs
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Objectives O
O O
Introduction to Microchip’s MCHPFSUSB USB Firmware Framework Introduction to the CDC Device Class Get hands-on experience in using Microchip’s Device Class USB Firmware − CDC Class: RS-232 Emulation API (AN956)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Agenda O O
USB Knowledge Check Device Classes & Microchip’s USB Device Class Firmware Solutions − Exercise 2.1 O
Play with the General Purpose Driver Demo
− Exercise 2.2 O
O O
Upload HID Mouse Example using Bootloader
Introduction to the USB CDC Device Class Specification Using the Microchip CDC Class Firmware: RS-232 Emulation API − Exercises 2.3.1 – 2.3.5 O
CDC RS-232 Emulation APIs
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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USB Knowledge Check O O O O O O
Maximum number of devices USB can support? Number of pins in USB connector? What is FS USB data rate? Which direction is Data-In? USB data transfer types? What is USB Enumeration?
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Device Classes & Microchip’s USB Device Class Firmware Solutions
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USB Device Classes -ReviewFloppy Drive
Data Glove
Ethernet Adapter
Mouse External Hard Drive PICkit 2 Joystick
Mass Storage Device Class (MSD)
Modem
Communication Device Class (CDC)
Keyboard
ICD2 Custom Class (Vendor Class)
Human Interface Device Class (HID)
Many more classes…. © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Using vs. Creating Device Class PIC18F4550
Control Transfer (SETUP, OUT, IN)
EP0
Chapter9
EP1 Device Class
Interrupt Bulk Isochronous
...
(OUT, IN)
EP15
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Human Interface Device (HID) PC Computer
PIC® Microcontroller HID\Mouse
Standard Windows Drivers
HID App
USB Cable
Design Considerations: • 64 KB/s max • Interrupt Transfer Type • Standard Windows driver • Custom PC application can access HID data through Win32 APIs © 2008 Microchip Technology Incorporated. All Rights Reserved.
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CDC - RS-232 Emulation PC Computer
PIC® Microcontroller CDC
Standard Windows Drivers
USB Cable
Hyper Terminal
INF File Required
Design Considerations: • ~80 KB/s max • PC applications can access the device as though it is connected to a serial COM port © 2008 Microchip Technology Incorporated. All Rights Reserved.
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General Purpose Driver PIC® Microcontroller
PC Computer
Boot MCHPUSB.sys MPUSBAPI.dll PDFSUSB.exe Demo Binary Only USB Cable INF File Required
Source and Binary
Other C++ Binary Only Examples Source and Binary
Design Considerations: • ~1,088 KB/s max • Very flexible • Not a standard Windows driver • PC programming is required © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Mass Storage Device (MSD) See AN1003: USB Mass Storage PIC® Microcontroller
PC Computer
MSD
Standard Windows Driver
Windows Explorer
USB Cable
Design Considerations: • Acts like a disk drive • Fast data transfer over USB • Speed is limited depending on the physical media interface • For usefulness, a File System should also be implemented in firmware © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Downloading the Microchip USB Framework
390_USB incorporates v1.3 of the Microchip USB Framework
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.1 & Exercise 2.2 - Objectives -
O
O O
O O
Familiarize you with the development environment We will not be writing any code Just compiling, programming Flash memory, and playing with the default demonstration Exercise 2.1: General Purpose Driver Demo Exercise 2.2: Upload HID mouse example using the bootloader
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MCHPFSUSB Firmware - Project
O
Folder Structure -
C:\MCHPFSUSB
Workspace file: MCHPUSB.mcw Output file: MCHPUSB.hex
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.1
- General Purpose Driver Demo O O
O O O
Launch MPLAB® IDE Import C:\MCHPFSUSB\fw\_factory_hex\ picdemfsusb.hex Select MPLAB ICD 2 as a programmer Program the device Remove the 9 inch modular cable and follow instructions in Chapter 3 of the PICDEM™ FS USB User’s Guide on how to run the demo.
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.2
- Download HID Mouse Demo via a Bootloader O O O O
O
Launch PDFSUSB.exe if you have not done so already Enter bootload mode by holding down push button S2 and hit S1 to reset Select Boot Mode Tab in PDFSUSB.exe Follow instructions in Chapter 3 of the User’s Guide on how to download a hex file Download: C:\MCHPFSUSB\fw\Hid\Mouse\output \MCHPUSB.hex
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Introduction to the USB CDC Device Class Specification
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“Virtual” COM Port Application HyperTerminal HyperTerminal
UART Driver
UART Driver
CDC Driver
UART Hardware
RS-232
USB Hardware
RS-232
USB
UART Hardware UART APIs Firmware Application
USB
USB Hardware
Microchip CDC RS-232 Emulation API
© 2008 Microchip Technology Incorporated. All Rights Reserved.
USB UART APIs
PIC18F4550
Firmware Application
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The Communications Device Class (CDC) O
Encompasses a variety of devices − “POTs (Plain Old Telephone Service)” devices O
Analog phones and modems, ISDN terminal adaptors, Cell phones, “Virtual” COM ports
− “Medium Speed” networking devices O
O
ADSL Modems, Cable Modems, Ethernet Adaptors
The USB Interfaces in these devices carry generic data as well as encapsulated application-specific command protocols, such as V25ter for modems (AT command set).
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Abstract Control Model (ACM) Serial Emulation (3.6.2.1) O O
ACM covers implementation of virtual COM ports 2 USB Interfaces are required − Communications Class Interface O O
1 - Int IN Ep Used to notify host of the current RS-232 connection status from the USB RS-232 emulated device
− Data Class Interface O O O
1 – Bulk IN Ep & 1 – Bulk OUT Ep Used to transfer raw data bytes that would normally be transferred over RS-232 Also may be used to send encapsulated call control (AT) commands
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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The “Logical” CDC-ACM USB Device Device (Manufacturer: Microchip Technology) (Product: CDC RS-232 Emulation Demo) (VID_PID: 04d8_000a)
Configuration#1 (Active)
Interface#1
Interface#0 (Communications Class Interface)
(Data Class Interface) Analog/Digital I/O
Endpoint 2 (Interrupt - IN)
usbser.sys
Endpoint 3 (Bulk - OUT)
Pipes
Endpoint 3 (Bulk - IN)
OS USB Control Pipes
MCHPFSUSB CDC TX/RX Functions
Endpoint 0 (Control - OUT)
Endpoint 0 (Control - IN)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Microchip CDC-ACM Firmware O
Summary of Class-specific requests & notifications implemented (see 6.2 & 6.3 in CDC specification for description): − The CDC firmware implements handlers for O O O O O
SEND_ENCAPSULATED_COMMAND GET_ENCAPSULATED_RESPONSE SET_LINE_CODING GET_LINE_CODING SET_CONTROL_LINE_STATE
− However, the CDC firmware currently returns a NAK to tell the host that no response is available O
O
i.e. – The CDC firmware will not issue reply to AT commands issued by the Host Application!! So – don’t use them! – You’re wasting USB bus bandwidth Only send/receive raw data
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Using the Microchip CDC Class RS-232 Emulation API (Exercise 2.3)
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Open The CDC Project Workspace O O
O O O
O
If using an ICD 2... Attach 9” Modular cable to the demo board Attach USB cable to the demo board Select “File/Open Workspace…” Open project C:\MCHPFSUSB\fw\CDC\MCHPUSB.mcw Do not do anything else just yet
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Configuration Bits
O
FS USB Clock Source: Clock src from 96 MHz PLL/2 CPU Sys Clk Postscaler: [OSC1/OSC2 Src: /1][96MHz PLL Src: /2] 96MHz PLL Prescaler: Div by 5 {20 MHz input} Oscillator: HS: HS+PLL, USB-HS USB Voltage Regulator: Enabled Watchdog Timer: Disabled PortB A/D Enable: configured as digital I/O on RESET Low Voltage Program: Disabled
O
The only file you will need to modify is user.c
O O O O O O O
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Clock Configuration Example Peripheral Device Board PIC18F4550 20 MHz EC
Divide by 5
96 MHz PLL
Divide by 2
Divide by 2
Accepts 4 MHz Input Only
48 MHz : 12 MIPs SIE
CPU Core
SIE Clock = 48 MHz : Full-Speed Mode
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Running the Default Code O O
O
O
Press F10 to compile project Select “Programmer\Select Programmer” and make sure that MPLAB® ICD 2 is selected Select “Programmer\Program” to download the code to the microcontroller Do not disconnect 9” Modular cable just yet
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Device Manager O
O
Open “Device Manager” and take a look at the “Ports (COM & LPT)” category Observe how many COM ports are currently there on your computer
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Device Manager O O
Now disconnect the 9” modular cable The device should be detected by Windows
You should see an additional ‘virtual’ COM port. Remember the number of the COM port
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Using HyperTerminal O O
Launch HyperTerminal Type in a name for a new connection, and hit “OK”
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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HyperTerminal: Connect To O
Select the new COM port that was added during USB CDC installation and hit “OK”
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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HyperTerminal: COM Properties O O
Hit “OK” Terminal is now ready
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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HyperTerminal: First Use O
Now, hit switch 2 on the demo board, you should see the message below…
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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HyperTerminal: Important Note O
Before physically disconnecting a USB device, you must hang up the connection first, otherwise, the program must be closed and opened again the next time a USB device is connected.
O
Let’s take a look at the APIs
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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CDC APIs void putrsUSBUSART(const rom char *data); void putsUSBUSART(char *data); void mUSBUSARTTxRom(rom byte *pData, byte len); void mUSBUSARTTxRam(byte *pData, byte len); byte getsUSBUSART(char *buffer, byte len); byte mCDCGetRxLength(void);
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Determinants of API O
O
Are you exchanging new-line terminated ASCII strings (canonical mode) or raw bytes (non-canonical mode) with the host application? Is the data stored in ROM or RAM?
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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API for Null-terminated Literal & ROM Data void putrsUSBUSART(const rom char *data); void putsUSBUSART(char *data); void mUSBUSARTTxRom(rom byte *pData, byte len); Use ‘putrs’ for literal and data stored in ROM
void mUSBUSARTTxRam(byte *pData, byte len); byte
Usage Example: putrsUSBUSART(“Hello”); or getsUSBUSART(char *buffer, putrsUSBUSART(welcome); where rom char welcome[]=(“Bye”);
byte len);
byte mCDCGetRxLength(void); © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Importance of Checking State O
O
O
cdc_trf_state − CDC_TX_READY − CDC_TX_BUSY − CDC_TX_BUSY_ZLP − CDC_TX_COMPLETING When calling an API that sends data to the host, must check that: cdc_trf_state == CDC_TX_READY Or use macro: − BOOL mUSBUSARTIsTxTrfReady(void); Returns ‘1’ when state is CDC_TX_READY
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Program Flow Reset
main
InitializeSystem
MainLoop
Cooperative Multitasking!! USBTasks()
No blocking functions. ProcessIO()
Use state machine.
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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main.c USBDriverService(); CDCTxService(); …
user.c Exercise_01(); Exercise_02(); …
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Cooperative Multitasking Main Loop State Machine
Task A.1 - 200 us Task A.2 - 400 us
Task A 900 us
Task A.3 - 300 us
Task B - 100 us
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.3.1
- Sending Literal Data O O
O O
Find function Exercise_01() in user.c Write code in this function that sends a literal nullterminated string of text (“Hello World!\r\n”) to the PC when switch 2 is pressed Take a look at examples in Exercise_Example(); Useful functions: − BOOL Switch2IsPressed(void); O O
O
Returns 1 if switch 2 was pressed Returns 0 if switch 2 was not pressed
− BOOL mUSBUSARTIsTxTrfReady(void) − Use: putrsUSBUSART(…) End of Exercise 2.3.1 Solution code:
C:\MCHPFSUSB\fw\Cdc\user\solutions\Exercise1.txt
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.3.2
- Sending ROM Data O O
O
Find function Exercise_02() in user.c Write code in this function that sends a null-terminated string of text stored in program memory pointed to by “ex02_string” to the PC when switch 3 is pressed Useful functions: − BOOL Switch3IsPressed(void); − BOOL mUSBUSARTIsTxTrfReady(void) − Use: putrsUSBUSART(…) End of Exercise 2.3.2
O
Solution code:
C:\MCHPFSUSB\fw\Cdc\user\solutions\Exercise2.txt
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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APIs for Receiving Data void putrsUSBUSART(const rom char *data); len = expected number of input buffer = pointer to user buffer of size void putsUSBUSART(char *data); equals to or larger than len getsUSBUSART returns numberbyte len); void mUSBUSARTTxRom(rom byte actual *pData, of bytes copied to user buffer
void mUSBUSARTTxRam(byte *pData, byte len); byte getsUSBUSART(char *buffer, byte len); byte mCDCGetRxLength(void); © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.3.3 - Receiving Data -
O O
Find function Exercise_03() in user.c Write code in this function that reads data from USB bus and toggles LED D4 when the data read equals ASCII character ‘1’ (0x31)
O
Useful functions & variables: − input_buffer[]; − mLED_4_Toggle(); − Use: getsUSBUSART(…) End of Exercise 2.3.3
O
Solution code:
C:\MCHPFSUSB\fw\Cdc\user\solutions\Exercise3.txt
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APIs for a String of Data with Known Length void putrsUSBUSART(const rom char *data); Use mUSBUSARTTxRom for data stored in program memory
void putsUSBUSART(char *data);
255-byte maximum
void mUSBUSARTTxRom(rom byte *pData, byte len); void mUSBUSARTTxRam(byte *pData, byte len); byte getsUSBUSART(char *buffer, byte len); Use mUSBUSARTTxRam for data stored in data memory
byte mCDCGetRxLength(void); © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.3.4
- Sending Non Null-terminated Data O O O O
O
Before starting, comment out call to Exercise_01() in ProcessIO() first Find function Exercise_04() in user.c Write code in this function that sends the following 4 bytes of data: 0x30,0x31,0x32,0x33 when switch 2 is pressed Useful functions & variables: − Switch2IsPressed(); − BOOL mUSBUSARTIsTxTrfReady(void) − output_buffer[]; − Use: mUSBUSARTTxRam(…) End of Exercise 2.3.4 Solution code: C:\MCHPFSUSB\fw\Cdc\user\solutions\Exercise4.txt
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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API for Null-terminated RAM Data void putrsUSBUSART(const rom char *data); void putsUSBUSART(char *data); void mUSBUSARTTxRom(rom byte *pData, byte len); ‘puts’ for data storedlen); in RAM void mUSBUSARTTxRam(byteUse*pData, byte
byte getsUSBUSART(char
Usage Example: putsUSBUSART(output_buffer); *buffer, byte len); where char output_buffer[]=(“Microchip”);
byte mCDCGetRxLength(void); © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 2.3.5
- Temperature Data O
Find function Exercise_05() in user.c The program currently outputs temperature data on the physical UART port. Change the program to output data through the USB port.
O
Follow instructions in Exercise_05()
O
Use mUSBUSARTIsTxTrfReady() Use putsUSBUSART(...)
O
O
End of Exercise 2.3.5 O
Solution code:
C:\MCHPFSUSB\fw\Cdc\user\solutions\Exercise5.txt
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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What is Wrong with This Code? void Exercise_XX(void) { putrsUSBUSART(“Hello World!”); }
Did not check:
if(mUSBUSARTIsTxTrfReady())
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What is Wrong with This Code? void Exercise_XX(void) { while(!mUSBUSARTIsTxTrfReady()); putrsUSBUSART(“Hello World!”); }
Answer: Blocking function! Not good for cooperative multitasking. CDCTxService() in USBTasks() will never get called, and cdc_trf_state will never be updated. Program will just be stuck in a loop. Remember, use a state machine!
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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CDC & COM-Port Numbering O
To prevent unwanted “COM-Port proliferation”
− Include a serial number in a string descriptor for any CDC class device you design. − A device that contains a serial number retains its COM port number even if moved to a different USB port on the system
O
Refer to Appendix G in the student handout for instructions how to do this.
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Post Exercise Analysis O
O O O
Speed − 640 Kbits/s = 80 Kbytes/s − Faster than RS-232 (UART) − This solution is not possible with a low-speed USB device because it does not have bulk endpoint No hardware handshakes Program Memory Usage: ~ 3 KB Application Note −
O
AN956: Migrating Applications to USB from RS-232 UART with Minimal Impact on PC Software
What to do if need faster data transfer rate? −
Use the custom class (“generic”) framework…and that’s just what we’re going to do next!
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Part 3. Using the Microchip General Purpose USB Windows® Driver and Custom Class Device Firmware
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Objectives O
O
Hands on experience using the Microchip General Purpose USB Driver for Microsoft Windows® Hands on experience using the Microchip Custom Class USB Firmware
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Agenda O O
PC Development Environment Windows® Basics
− Windows Architecture − .NET − Windows Application Development with Visual C++ 2005 Express − Windows Programming Principles − Static/Dynamic Linked Libraries − USB Driver Choices
O
Microchip General Purpose USB Driver − MPUSBAPI.DLL and mchpusb.sys − .inf Files
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Agenda Continued O
The MPUSBAPI.DLL Functions − Function List − MPUSBGetDLLVersion( ) O
O
Exercise 3.1 – Create a Win32 Console Application
PC-Device Data Exchange (PC Application Code) − A simple command/response protocol − PC-Side Flow Chart − MPUSBGetDeviceCount( ), MPUSBOpen(), MPUSBRead(), MPUSBWrite(), MPUSBClose()
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Agenda Continued O
PC-Device Data Exchange (Device Application Code) − Review of the Device-side Firmware Framework O
O O
Exercise 3.2 – Implement “Read Pot” Command
Error Handling & Error Codes Summary
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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PC Development Environment O
O
O O
PC connected to PICDEM™ FS USB demo board
PIC18F4550 loaded with default demo firmware, which implements the custom class (generic) USB firmware drivers.
Microsoft Visual C++ Express 2005 Microsoft Platform SDK 2003 R2
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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PC Environment
- Setting Up Visual C++ 2005 Express O O O O O O
Download & install “Visual C++ 2005 Express Edition” Download & Install Microsoft Platform SDK Update VC++ 2005 directories Update corewin_express.vsprops Update AppSettings.htm Step by step directions available in your class handout
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MCHPFSUSB Firmware - Project Folder Structure -
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® Windows
Basics
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Windows XP Operating System O
Based on Windows NT/OS2 −
O
Function −
O
Designed by David Cutler (Designer of DECs VMS OS)
To manage the hardware and provide an environment in which a user can execute programs in a convenient and efficient manner.
Essential Features − − − −
Memory: large, flat, virtual memory address space File systems, console, and other I/O Multitasking: processes and threads Communication and synchronization O
−
Single user and networked
Security
Windows Architecture le o s ns n o tio C a s c i w pl o d Ap in W
UI s G s ion w at o d lic n i W A pp
MPUSBRead( )
MPUSBWrite( )
User DLLs, Win32 Environment Subsystem, System Libraries (NTDLL.DLL) USER
NTReadFile( ), NTWriteFile( )
KERNEL
I/O Manager, & Graphics, Device and File System Drivers (.SYS) I/O Request Packet(s) (IRP)
Hardware © 2008 Microchip Technology Incorporated. All Rights Reserved.
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.NET Framework le o s ns n Co atio T lic E .N pp A
Managed Code
UI s G s ion m at r Fo plic s p w A o d in W
.NET Framework Class Library Assemblies (DLLs) MPUSBRead( )
Unmanaged Code
MPUSBWrite( )
User DLLs, CLR DLLs, Win32 Environment Subsystem, System Libraries (NTDLL.DLL) USER
NTReadFile( ), NTWriteFile( )
KERNEL
Kernel © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Windows Application Development - Visual C++ 2005 Express -
O
With Visual C++ 2005 Express Edition you have two basic ways of creating a interactive, graphical application: − Using the Windows API (Win32 USER Functions) O
Most programming intensive
− Using Windows Forms (.NET Framework) O
O
Least programming intensive
Visual C++ 2005 Express Edition also allows you to create two types of console application (Win32 and CLR (.NET)) − We will be developing a “Win32 Console” ANSI-C application
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Windows Programming Principles
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Windows Programming Principles – Handles O O O
Nearly every resource is an “object” identified and referenced by a “handle” of type HANDLE Kernel objects must be manipulated by WindowsAPIs HANDLE datatype objects include: − files − processes − threads
O
pipes memory mapping events, mutexes, semaphores
Windows is rich and flexible
− Many functions perform the same or similar operations − Each function has numerous parameters and flags
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Windows Programming Principles – Notation/Types O
Long and descriptive −
O
Predefined descriptive data types in upper case −
O
BOOL, DWORD, LPDWORD, ...
Predefined types avoid the * operator and make distinctions: − −
O
WaitForSingleObject WaitForMultipleObjects
LPTSTR (defined as TCHAR *) and LPCTSTR (defined as const TCHAR *)
Variable names in Win32 API descriptions use “Hungarian” notationÆrequires that a variable be prefixed with an abbreviation of its data type −
lpFileName — long pointer [to a zero terminated string]
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Writing Windows (Win32) Programs O
is always included
O
All objects identified by variables of type HANDLE −
O
Symbolic constants and flags which explain their meaning −
O
CloseHandle function applies to (nearly) all objects
INVALID_HANDLE_VALUE and GENERIC_READ
ReadFile, WriteFile, and many other Windows
functions return Boolean values
− System error codes obtained through follow-up call to GetLastError ()
O
Standard C library always available (fopen() etc) − But you cannot fully exploit Windows with it
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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DLLs
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Library Linking O O
Library – A set of functions useable by user programs Static linking: −
O
Static Linked
Dynamic Linked
10010101..
10010101..
10010101..
10010101..
Compiler
Dynamic Linking: − −
OS Benefits O
O
O O
The application stores references only, so application size reduces compared to static linking Only one copy of common data and common resources are maintained in memory Leads to better utilization available memory Modularization at the OS level
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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DLLs – Win32 Application Run Time Linking O
O
O
User DLL (MPUSBAPI.DLL) functions explicitly loaded & unloaded when needed Program must explicitly get function addresses Windows® Win32 API calls: − LoadLibrary − FreeLibrary − GetProcAddress
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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O
O
DLLs – .NET Application Run Time Linking No need to explicitly get function addresses using LoadLibrary, GetProcAddress, FreeLibrary Bridge to “unmanaged” code:
[DllImport("MPUSBAPI.dll")] extern "C" © 2008 Microchip Technology Incorporated. All Rights Reserved.
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USB Driver Choices Generic Data Transfer
V1.10 Feb 28, 2008 © 2007 2008 Microchip Technology Incorporated. All Rights Reserved.
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mchpusb.sys vs. HID vs. CDC Features
mchpusb.sys (v1.0.0.6)
HID
CDC
Driver support built into Windows 64-bit PC Support
No
Yes
Yes (need .inf)
Yes
Yes
Yes
XP Ready
Yes
Yes
Yes
Vista Ready
Yes
Yes
Yes
Control
Yes
Yes
No
Interrupt
Yes
Yes
No
Bulk
Yes
No
Yes
~1.0 MB/s
64KB/s
~80kByte/s
Transfer Types
Max Speed
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Other generic drivers… O
LibUSB − Open Source − Supports Windows and Linux − Supports Interrupt, Bulk, and Isochronous transfers
O
− http://libusb-win32.sourceforge.net/ WinUSB − Supported in Vista only − Supports Interrupt and Bulk − http://msdn2.microsoft.com/enus/library/aa476426.aspx
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Microchip General Purpose Windows® USB Device Driver
V1.10 Feb 28, 2008 © 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBAPI
- Introduction O
O O O O O O
Wrapper Code for Win32 API system call functions (which ultimately communicate with mchpusb.sys) Works with all Microchip USB Devices Works with Visual C++ .NET, C++ Builder, Visual Basic .NET, and more… Easy & Flexible data transfer Supports Bulk and Interrupt transfers Functional interface simplifies application development Free
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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O
O O
Microchip General Purpose USB Device Driver mchpusb.inf – This file contains the information about the device driver mchpusb.sys - Microchip USB Device Driver These files can be found in the following path − C:\MCHPFSUSB\Pc\MCHPUSB Driver\Release
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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mchpusb.inf O O O
.inf file tells windows how to configure and use a device Device Manager reads the VID and PID from the target device Windows uses .inf file to: − Associates driver to use with VID & PID − Specifies device identification strings − Specifies source and destination of device files − Sets registry keys
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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.inf File Modifications O
Modifiable sections in mchpusb.inf − [DeviceList] O
%DESCRIPTION%=DriverInstall, USB\VID_04D8&PID_000B, USB\VID_04D8&PID_000C
− [Strings] O
ONEYSOFT="Walter Oney Software" MFGNAME="Microchip Technology, Inc." INSTDISK="Microchip Technology, Inc. Installation Disc" DESCRIPTION="PIC18F4550 Family Device"
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Using MPUSBAPI.DLL
O
For Run-Time Linking Applications − #include “mpusbapi.h” − Must use LoadLibrary, GetProcAddress, and FreeLibrary Win32 API calls on mpusbapi.dll
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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The MPUSBAPI.DLL Functions
V1.10 Feb 28, 2008 © 2007 2008 Microchip Technology Incorporated. All Rights Reserved.
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Functions in MPUSBAPI.DLL MPUSBAPI Functions MPUSBGetDeviceCount(..)
VID & PID
MPUSBOpen(..) MPUSBClose(..)
MPUSBReadInt( .. ) MPUSBRead( .. ) MPUSBWrite( .. )
VID & PID MPUSBGetDLLVersion( .. ) © 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBGetDLLVersion( ) O
DWORD MPUSBGetDLLVersion (void)
− Returns −32-bit revision level MMMMmmmm −MMMM – 16-bit Major Version# −mmmm – 16-bit Minor Version#
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Part 3. Hands-on Exercises O
PC-Side Lab Source Files are in the following directory: C:\RTC\390_USB\Pc\Ex3\Ex3.N\Ex3.N (N is the number of the exercise)
O
Device-Side workspace is here (Ex3.2 Only): C:\RTC\390_USB\fw\Ex3.2\MCHPUSB.mcw
O
To do the labs: Open the soft-copy of the class handout and build the solution code step-by-step by cutting-and-pasting code pieces into the source code editor (MPLAB IDE and/or Visual Studio): C:\RTC\390_USB\Presentation & Handouts\390_USB v1.05 Handout.doc
O
Solution projects/workspaces are here: PC: Device:
C:\RTC\390_USB\Pc\Ex3\Ex3.N_solution\Ex3.N_solution.sln C:\RTC\390_USB\fw\Ex3.2_solution\MCHPUSB.mcw
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 3.1
- Creating a Win32 Console Application O
Objective
− Get familiarized with the Visual C++ 2005 programming environment
O
Concepts to learn
− Creating/compiling/executing a basic Win32 Console application − How to load/unload MPUSBAPI DLL functions at run-time − Using MPUSBGetDLLVersion( )
O
To do
− Follow the instructions in the handout
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Exercise 3.1 – Results O
Press Ctrl+F5 to run
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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PC-Device Data Exchange (PC Application Code)
V1.10 Feb 28, 2008 © 2007 2008 Microchip Technology Incorporated. All Rights Reserved.
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A Simple Protocol O O O
O
PC opens a communications “pipe” to a device endpoint PC-Device exchange command/response “buffers” Based on the “Demo” fw application and “_console” Pc application in MCHPFSUSB Full command set defined in Appendix A of the handout
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Example: READ_POT O
Command Code: 0x37 − PC sends 0x37 − Device Returns
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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PC-Side Flow Chart Load Library Get Procedure Addresses
MPUSBGetDeviceCount( ) MPUSBOpen( )
Open Endpoints Load command buffer
MPUSBWrite( )
Send command buffer
MPUSBRead( )
Read response Buffer Print Response
MPUSBClose( )
Close Endpoints Free Library
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBGetDeviceCount( ) O
DWORD MPUSBGetDeviceCount(PCHAR pVID_PID) − Passed: O
pVID_PID – a pointer to a VID_PID string − String Format: "vid_xxxx&pid_yyyy“ − xxxx is VID value in HEX − yyyy is PID value in HEX
− Returns: O
O
The number of attached devices with matching VID&PID (also referred to as the number of instances) Before you can open a handle (pipe) to an endpoint on a specific board (using MPUSBOpen( )), your program must determine the valid instance index of this board.
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Finding the Valid Instance Index Numbers for a given VID&PID Application must run the following code after calling MPUSBGetDeviceCount( ) // The // // // // // //
total number of devices using the generic driver could be bigger than max_count. They could have different vid & pid numbers. This means if max_count is 2, the valid instance index do not necessary have to be '0' and '1'. Below is a sample code for searching for all valid instance indexes. MAX_NUM_MPUSB_DEV is defined in _mpusbapi.h
count = 0; for(int i = 0; i < MAX_NUM_MPUSB_DEV; i++) { tempPipe = MPUSBOpen(i,vid_pid,NULL,MP_READ,0); if(tempPipe != INVALID_HANDLE_VALUE) { printf("Instance Index # %d\r\n",i); MPUSBClose(tempPipe); count++; } if(count == max_count) break; }//end for
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBOpen( ) O
HANDLE MPUSBOpen (DWORD instance, // Input PCHAR pVID_PID, // Input PCHAR pEP, // Input DWORD dwDir, // Input DWORD dwReserved);//Input − Passed: O O O
instance – a valid instance index number pVID_PID – a pointer to valid VID&PID string pEP – a pointer to a valid Endpoint String O
O
“\\MCHP_EPz“ or “\\MCHP_EPz_ASYNC” or “NULL”
dwDir – Indicates the direction of the end-point O O
MP_READ – IN end point MP_WRITE – OUT end point
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBOpen( ) O
MPUSBOpen( ) continued: − Returns: O
This function returns a handle (“pipe”) to an end-point of the USB Device with (valid) instance, pVID_PID pEP, and dwDir
O
Return Value can be INVALID_HANDLE_VALUE
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBClose( ) O
BOOL MPUSBClose (HANDLE handle);
//Input
− Closes the handle (pipe) to an end point − Arguments O
Handle – Handle to the IN end-point
− Returns O
BOOL – Success (1) Failure (0)
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBWrite( ) O
DWORD MPUSBWrite (HANDLE handle, PVOID pData, DWORD dwLen, PDWORD pLength, DWORD dwMilliseconds);
O O
// // // // //
Input Input Input Output Input
Writes pData buffer to an OUT end-point Arguments: − − − − −
Handle – Handle to the OUT end-point pData – Buffer dwLen – Number of bytes to be written pLength – Number of bytes actually written dwMilliseconds – Time Out Period
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBRead( ) O
DWORD MPUSBRead (HANDLE handle, // Input PVOID pData, // Output DWORD dwLen, // Input PDWORD pLength, // Output DWORD dwMilliseconds);// Input − Reads from the IN end-point and fills a buffer − Arguments O O O O O
Handle – Handle to the IN end-point pData – Buffer dwLength – Number of bytes to be read pLength – Number of bytes actually read dwMilliseconds – TimeOut period
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBReadInt( ) O
DWORD MPUSBReadInt HANDLE handle, PVOID pData, DWORD dwLen, PDWORD pLength, DWORD dwMilliseconds);
O O O
// // // // //
Input Output Input Output Input
Reads from an Interrupt IN end-point and fills a buffer The user application should call MPUSBReadInt() often enough to avoid data losses Arguments: − − − − −
handle – Handle to the IN end-point pData – Buffer (pointer to array of integers) dwLen – Number of bytes to be read (should match report size) pLength – Number of bytes actually read dwMilliseconds – Time Out Period
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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MPUSBRead or MPUSBReadInt? O O
Is the device “Synchronous” or “Asynchronous”? A Synchronous device operates in lock step with host application − MPUSBWrite() sends command − MPUSBRead() reads the response
O
An Asynchronous device returns data without prompt from host − Ex. An HID device produces “periodic reports” which are read regularly by the host − MPUSBReadInt( ) returns one “report” at a time
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Summary - DLL Function Transfer Type Usage Transfer/ Endpoint Type
Functions
Time-Out Applicable? Yes
Interrupt-OUT
MPUSBRead, MPUSBReadInt MPUSBWrite
Bulk-IN
MPUSBRead
Yes
Bulk-OUT
MPUSBWrite
Yes
Isochronous-IN
MPUSBRead
No
Isochronous-OUT
MPUSBWrite
No
Interrupt-IN
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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DLL Read/Write Usages O
O
App issues multiple reads or writes to device App issues one Read or Write specifying up to 64KBytes
USB Stack UserAPP MPUSBAPI.DLL MCHPUSB.SYS USBHUB.SYS USBPORT.SYS USBEHCT.SYS USBHW.SYS
− Driver splits data over multiple operations
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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PC-Device Data Exchange (Device Application Code)
V1.10 Feb 28, 2008 © 2007 2008 Microchip Technology Incorporated. All Rights Reserved.
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Microchip Custom Class Device Firmware (“Demo”) O O O O O
Custom Class Firmware API Defining commands Polling loop Initializing Peripherals Setting up the Descriptor Tables − VID & PID − Bulk/Interrupt − Strings
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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Custom Class Firmware API - See usbgen.c & usbgen.h -
O
void USBGenInitEP(void); − −
O
void USBGenWrite(byte *buffer, byte len); −
O
Macro checks if the OUT Ep is busy (owned by the SIE or not)
(bit) mUSBGenTxIsBusy(void); −
O
Copies data from the Ep buffer to the user’s buffer
(bit) mUSBGenRxIsBusy(void); −
O
Copies data from user’s buffer to the Ep buffer
byte USBGenRead(byte *buffer, byte len); −
O
Called after a SET CONFIGURATION request Initializes endpoints, state machine and variables
Macro checks if the IN Ep is busy (owned by the SIE or not)
byte mUSBGenGetRxLength(void); − Retrieves the number of bytes copied into theuser’s buffer after the most recent call to USBGenRead() © 2008 Microchip Technology Incorporated. All Rights Reserved.
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Custom Class (“Demo”) Firmware Structure Synchronous model O
O O
Accepts commands from host Returns results Waits for next command
Initialize
USB Tasks()
Process IO()
ServiceRequests()
© 2008 Microchip Technology Incorporated. All Rights Reserved.
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ServiceRequests( ) - Flow DiagramSTART
Yes
USB Packet Clear “counter” Received? USBGenRead()
Evaluate “dataPacket.CMD”
No Execute command function (
