Cypress EZ-USB FX2 USB Microcontroller

Official documentation: http://www-corot.obspm.fr/COROT-ETC/Files/CY7C68013.pdf

Details of the FX2 microcontroller...

The following loops were examined from [source:/gnuradio/trunk/usrp/firmware/src/usrp2/usrp_main.c usrp_main.c].

main( )

  • Initialize USRP
  • Initialize GPIF
  • Patch USB Descriptors (read from EEPROM, set HW device ID)
  • Setup Autovectors
  • Install USB Handlers
  • Re-enumerate
  • Run main_loop( )

main_loop( )

  1.  Check for USB setup packets
  2.  Check and log RX Overruns/TX Underruns
  3.  Check for packets to send back to host
  4.  Check for packets to send to FPGA

USB Endpoints

Different USB endpoints are used to logically separate different operations occuring on the bus into separate flows. There are currently 3 USB endpoints checked/used within the main_loop( ) as described earlier.


 Endpoint
Description

0
Control/status

2
Host -> FPGA

6
FPGA -> Host

USB Transfers

Describe typical USB transfers. Always 512-byte bulk transfers. Link to in-band signaling information.

All control information is written using endpoint 0 and the vendor commands. These commands are separated into two different categories: VRT_VENDOR_IN and VRT_VENDOR_OUT. These are processed in the app_vendor_cmd( ) function seen in [source:/gnuradio/trunk/usrp/firmware/src/usrp2/usrp_main.c usrp_main.c].

All control communication between the FPGA and FX2 microcontroller is done over the SPI. Daughterboards all seem to be controlled by the generic VRQ_I2C_* and VRQ_SPI_* commands.

VRT_VENDOR_IN Commands

  • VRQ_GET_STATUS
    • GS_TX_UNDERRUN
    • GS_RX_OVERRUN
  • VRQ_I2C_READ
  • VRQ_SPI_READ

VRT_VENDOR_OUT Commands

  • VRQ_SET_LED
  • VRQ_FPGA_LOAD
    • FL_BEGIN
    • FL_XFER
    • FL_END
  • VRQ_FPGA_SET_RESET
  • VRQ_FPGA_SET_TX_ENABLE
  • VRQ_FPGA_SET_RX_ENABLE
  • VRQ_FPGA_SET_TX_RESET
  • VRQ_FPGA_SET_RX_RESET
  • VRQ_I2C_WRITE
  • VRQ_SPI_WRITE





注：Cypress EZ-USB FX2 USB Microcontroller（原文出处，翻译整理仅供参考!）