FreeCalypso > hg > freecalypso-hwlab
view eeproms/icestick @ 167:8ffcd88d40c3
eeproms: fc-jtag gives way to jtagbuf
author | Mychaela Falconia <falcon@freecalypso.org> |
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date | Mon, 31 Jul 2023 00:34:38 +0000 |
parents | 7a4e8d23ab3a |
children |
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# Lattice iCEstick FPGA board features an FT2232H chip, with Channel A wired # for MPSSE mode (access to SPI flash and FPGA configuration controls) and # Channel B wired as a UART for user logic implemented in the FPGA. This # FT2232H subsystem includes a 93C56 EEPROM, but boards are shipped with it # blank, causing the FT2232H chip to take its default VID:PID. # # Having this default VID:PID causes undesirable behavior under Linux: a pair # of ttyUSB devices is created upon plug-in, but the first of these two then # disappears when the developer runs iceprog to manipulate FPGA programming, # creating a gap in ttyUSB device numbers. And even if you are working with a # stable logic design and not running iceprog, the first of the two created # ttyUSB devices is still bogus, as that hardware channel is wired for MPSSE # and not UART. # # In Falconian queendom, the solution to this problem is to program the EEPROM # behind the FT2232H chip with our own image and set the USB ID to a code that # tells the Linux kernel to create a ttyUSB device only for Channel B - the # so-called "JTAG quirk". Falconia Partners LLC got a block of 8 PIDs # officially allocated to us by FTDI, and since 2020-09 the mainline Linux # kernel recognizes two of them as JTAG quirks. Use one of those two PIDs. vid 0x0403 # FTDI pid 0x7150 # Allocated by FTDI to Falconia, JTAG quirk in Linux manuf Lattice product ICE40HX1K-STICK-EVN