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