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New method of video transfer and control functions for training in computer classroom and

EU CRAFT PROJECT 016357. New method of video transfer and control functions for training in computer classroom and for audiovisual applications. WP3: USB submodule. SCREENS – Tallin, 15 june 2006. USB module. HUB. ARM7. CONNECTOR To VIDEO BOARD. USB controller.

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New method of video transfer and control functions for training in computer classroom and

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  1. EU CRAFT PROJECT 016357 New method of video transfer and control functions for training in computer classroom and for audiovisual applications WP3: USB submodule SCREENS – Tallin, 15 june 2006

  2. USB module HUB ARM7 CONNECTOR To VIDEO BOARD USB controller SCREENS – Tallin, 15 june 2006

  3. USB module block diagram USB HOST PORT USB HUB Internal FLASH LPC221x ISP1161A USB DEVICE PORT UART0 UART1 + DIR FLAGS CONNECTOR To VIDEO BOARD to host to MOUSE to/from RS485 to/from AVR to KBD Debug UART SCREENS – Tallin, 15 june 2006

  4. Software architecture USB device driver USB host driver USB hub USB host service thread USB device service thread Mode Supervisor & error management A B RS485 protocol thread C AVR flags D Packet queue RS-485 network for USB data SCREENS – Tallin, 15 june 2006

  5. Operating modes MODE AVR CODE A B C D LOCKED 1 - - - - STANDALONE 0 Y Y - - REMOTE CONTROLLED 2 Y - - Y REMOTE CONTROLLER 3 - Y Y - USB host service thread USB device service thread A B RS485 protocol thread C D Packet queue SCREENS – Tallin, 15 june 2006

  6. USB stack selection, 1 • Commercial options: • Express Logic • Jungo • RTCX Traditional stacks on the market focus on mass storage (host and device) and HID class (device only); host and device stack are often sold separately. Typical NRE fees range from 20k euros to 60k euros for the combined host & device stack; a minimum license quantity must be purchased in advance. Homegrown minimal USB stack that matches requirements starting from Philips libraries SCREENS – Tallin, 15 june 2006

  7. USB stack selection, 2 • Philips semiconductors offers unsupported libraries dedicated to the ISP1161A for host and device control. • Available under NDA only, no fees associated • three sw models: host only, device only, simultaneous host and device • DOS version: does not assume presence of an underlying OS with USB libraries • bugs are present ISP1161x Simultaneous Host-and-Device Mode Software Model SCREENS – Tallin, 15 june 2006

  8. Development tools selection, 1 • Several alternatives available: • Keil MDK-ARM: RealView Microcontroller Development Kit for the ARM • IAR Embedded Workbench • Rowley Associates Crossworks for ARM • Green Hills (too expensive) • And the winner was……… • Reasons: • Lowest cost • supports inexpensive JTAG probes • based on GNU tools • dedicated to ARM7 devices • good feeling during the 30-day evaluation period • Highlights: • CrossStudio Integrated IDE • integrated programming of internal FLASH (not available on all competitors) SCREENS – Tallin, 15 june 2006

  9. Development tools selection, 2 SCREENS – Tallin, 15 june 2006

  10. Development tools selection, 3 • Crossworks • Support packages for the following processors: • Atmel AT91SAM7 (ARM7 core) • Luminary Micro LM3Sxxx (ARM Cortex M3 core) • Philips LPC2xxx (ARM7 core) • ST Microelectronics STA2051, STR71x, STR31x (ARM7) • SHARP LH75401, LH79520, LH79524 • Several development boards are supported with specific code; among them: • Olimex LPC-E2214 (a superset of the LPC-H2214 we have been using) SCREENS – Tallin, 15 june 2006

  11. Development tools selection, 4 Board used for getting more familiar with the microcontroller OLIMEX LPC-H2214 • Inexpensive • micro + SRAM + FLASH + serial ports (one of them via USB2serial converter) SCREENS – Tallin, 15 june 2006

  12. Test environment, 1 PHASE A: analysis on host of USB transactions Using an open-source application for Windows, we have analyzed USB Messages between host controller and USB peripheral • USB Snoopy: USB trafficviewer • Works on a Windows machine • it translates all data sent and received by the original windows driver in • a more human readable form and writes this result in a big ascii file http://sourceforge.net/projects/usbsnoop/ Alternative: Bus Hound, commercial product from Perisoft: www.perisoft.com SCREENS – Tallin, 15 june 2006

  13. Test environment, 2 PHASE A: analysis on host of USB transactions SCREENS – Tallin, 15 june 2006

  14. Test environment, 3 ______________________________________________________________________________ 1 in down n/a 0.219 GET_DESCRIPTOR_FROM_DEVICE URB Header (length: 80) SequenceNumber: 1 Function: 000b (GET_DESCRIPTOR_FROM_DEVICE) ________________________________________________________________________________ 1in up n/a 0.235 CONTROL_TRANSFER12 01 10 01 00 00 00 080x00000000 URB Header (length: 80) SequenceNumber: 1 Function: 0008 (CONTROL_TRANSFER) PipeHandle: 82ff64a8 SetupPacket: 0000: 80 06 00 01 00 00 12 00 bmRequestType: 80 DIR: Device-To-Host TYPE: Standard RECIPIENT: Device bRequest: 06 GET_DESCRIPTOR Descriptor Type: 0x0001 DEVICE TransferBuffer: 0x00000012 (18) length 0000: 12 01 10 01 00 00 00 08 6d 04 0c c0 10 21 01 02 0010: 00 01 bLength : 0x12 (18) bDescriptorType : 0x01 (1) bcdUSB : 0x0110 (272) bDeviceClass : 0x00 (0) bDeviceSubClass : 0x00 (0) bDeviceProtocol : 0x00 (0) bMaxPacketSize0 : 0x08 (8) idVendor : 0x046d (1133) idProduct : 0xc00c (49164) bcdDevice : 0x2110 (8464) iManufacturer : 0x01 (1) iProduct : 0x02 (2) iSerialNumber : 0x00 (0) bNumConfigurations : 0x01 (1) Downstream (from host to device) Upstream (device reply) connecting a USB mouse Retrieval of device descriptor SCREENS – Tallin, 15 june 2006

  15. Test environment, 4 ________________________________________________________________________________ 2 in down n/a 0.235 GET_DESCRIPTOR_FROM_DEVICE URB Header (length: 80) SequenceNumber: 2 Function: 000b (GET_DESCRIPTOR_FROM_DEVICE) ________________________________________________________________________________ 2 in up n/a 0.235 CONTROL_TRANSFER 09 02 22 00 01 01 00 a0 0x00000000 URB Header (length: 80) SequenceNumber: 2 Function: 0008 (CONTROL_TRANSFER) PipeHandle: 82ff64a8 SetupPacket: 0000: 80 06 00 02 00 00 09 00 bmRequestType: 80 DIR: Device-To-Host TYPE: Standard RECIPIENT: Device bRequest: 06 GET_DESCRIPTOR Descriptor Type: 0x0002 CONFIGURATION TransferBuffer: 0x00000009 (9) length 0000: 09 02 22 00 01 01 00 a0 32 bLength : 0x09 (9) bDescriptorType : 0x02 (2) wTotalLength : 0x0022 (34) bNumInterfaces : 0x01 (1) bConfigurationValue: 0x01 (1) iConfiguration : 0x00 (0) bmAttributes : 0xa0 (160) MaxPower : 0x32 (50) Downstream (from host to device) Upstream (device reply) connecting a USB mouse Retrieval of configuration descriptor SCREENS – Tallin, 15 june 2006

  16. Test environment, 5 ________________________________________________________________________________ 5 out down n/a 0.281 CLASS_INTERFACE - URB Header (length: 80) SequenceNumber: 5 Function: 001b (CLASS_INTERFACE) PipeHandle: 00000000 SetupPacket: 0000: 22 0a 00 00 00 00 00 00 bmRequestType: 22 DIR: Host-To-Device TYPE: Class RECIPIENT: Endpoint bRequest: 0a No TransferBuffer ________________________________________________________________________________ 5 out up n/a 0.281 CONTROL_TRANSFER - 0x00000000 URB Header (length: 80) SequenceNumber: 5 Function: 0008 (CONTROL_TRANSFER) PipeHandle: 82ff64a8 SetupPacket: 0000: 21 0a 00 00 00 00 00 00 bmRequestType: 21 DIR: Host-To-Device TYPE: Class RECIPIENT: Interface bRequest: 0a No TransferBuffer connecting a USB mouse Retrieval of class type SCREENS – Tallin, 15 june 2006

  17. Board under test, 1 SCREENS – Tallin, 15 june 2006

  18. Board under test, 2 Serial-to-USB converter USB connector adapter (replicating USB connectors on Video Board) ARM7 JTAG emulator debug serial port SCREENS – Tallin, 15 june 2006

  19. RS-485 protocol, 1 • Low-level protocol: binary, with 8-bit CRC and escape sequences (to avoid persistent out-of-sync situations) • General data packet: • <STX> <CMD> <LEN> <data>…<data> <CRC> <EOX> • where: • STX = Start of Packet • CMD = command (write, read) • LEN = number of data bytes, excluding CRC; it may be zero • CRC = CRC of all bytes from CMD to last data • EOX = End of Packet • STX, EOX: unique byte values • If the same must transmitted, it is substituted with a 2-byte sequence, as follows: • STX = 0x02, EOX = 0x04, ESC = 0x10 • Inserted data byte = value OR 0x80 (modified since last meeting) • Then: • 0x10 0x82 means a value of 0x02 • 0x10 0x84 means a value of 0x04 • 0x10 0x90 means a value of 0x10 SCREENS – Tallin, 15 june 2006

  20. RS-485 protocol, 2 Internal debug tool for exercising the RS-485 protocol on standard RS-232 connection; protocol is decoded on-the-fly SCREENS – Tallin, 15 june 2006

  21. RS-485 protocol, 3 STX CRC CMD data[0] LEN EOX SCREENS – Tallin, 15 june 2006

  22. Current status • Hardware realization • PCB layout completed, prototype fabrication completed • fully RoHS compliant • power control of USB ports included • prototypes debugged and in use • Software development • RS-485 protocol completed • low-level driver for ISP1161A completed • minimal USB host stack completed • minimal USB device stack completed • debug, integration and fine tuning: in progress SCREENS – Tallin, 15 june 2006

  23. THANK YOU SCREENS – Tallin, 15 june 2006

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