FreeCalypso > hg > freecalypso-hwlab
comparison eeproms/jtag-unbuf @ 32:60b8cf977c3f
unbuffered JTAG adapters: ID assigned and EEPROM config created
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Sun, 21 Apr 2019 06:27:11 +0000 |
| parents | |
| children | ace3ed1d5ddf |
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| 31:16b625911e19 | 32:60b8cf977c3f |
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| 1 # This EEPROM configuration is meant to be programmed into COTS FT2232D | |
| 2 # breakout boards used as unbuffered JTAG adapters. The custom USB VID:PID | |
| 3 # belongs to Falconia Partners LLC; we hereby allow the community to program | |
| 4 # this PID into generic FT2232D boards (not made by Falconia) as long as | |
| 5 # it is used for the present purpose with this full EEPROM configuration. | |
| 6 # | |
| 7 # The purpose of having a custom USB ID is to prevent the Linux kernel | |
| 8 # from treating this FT2232D instance as a dual UART and creating a | |
| 9 # ttyUSB device for Channel A; if you wish to use Channel B as a UART | |
| 10 # (which is still available for that purpose), you will need to make a | |
| 11 # one-liner patch to the ftdi_sio driver, telling it to treat this USB ID | |
| 12 # like other JTAG+UART adapters, creating a ttyUSB device only for Channel B. | |
| 13 | |
| 14 vid 0x0403 # FTDI | |
| 15 pid 0x7151 # Allocated by FTDI to Falconia Partners LLC | |
| 16 manuf FTDI | |
| 17 product Unbuffered JTAG adapter | |
| 18 | |
| 19 # We program Channel A to come up in the 245 FIFO mode prior to being | |
| 20 # switched into MPSSE mode by OpenOCD, as opposed to the default 232 UART mode. | |
| 21 # If the FT2232D chip's ADBUS pins are connected directly to the JTAG target | |
| 22 # without a buffer (what we mean by an unbuffered JTAG adapter), the default | |
| 23 # 232 UART mode is NOT safe, as it will produce a fight on the ADBUS2 line | |
| 24 # between the UART RTS output and the target's TDO output. 245 FIFO mode is | |
| 25 # expected to be safer, as all 8 ADBUS lines will be inputs for as long as | |
| 26 # ACBUS2 and ACBUS2 are left unconnected and not driven by anything. | |
| 27 | |
| 28 byte00 0x01 # Channel A: FIFO mode, D2XX driver | |
| 29 byte01 0x08 # Channel B: UART mode, VCP driver |