Advanced usage of openFPGALoader¶

Resetting an FPGA¶

openFPGALoader [options] -r

Using negative edge for TDO’s sampling¶

If transaction are unstable you can try to change read edge by using

openFPGALoader [options] --invert-read-edge

Reading the bitstream from STDIN¶

cat /path/to/bitstream.ext | openFPGALoader --file-type ext [options]

--file-type is required to detect file type.

Note

It’s possible to load a bitstream through network:

# FPGA side
nc -lp port | openFPGALoader --file-type xxx [option

# Bitstream side
nc -q 0 host port < /path/to/bitstream.ext

Automatic file type detection bypass¶

Default behavior is to use file extension to determine file parser. To avoid this mechanism --file-type type must be used.

FT231/FT232 bitbang mode and pins configuration¶

FT232R and ft231X may be used as JTAG programmer. JTAG communications are emulated in bitbang mode.

To use these devices user needs to provides both the cable and the pin mapping:

openFPGALoader [options] -cft23XXX --pins=TDI:TDO:TCK:TMS /path/to/bitstream.ext

where:

ft23XXX may be ft232RL or ft231X.
TDI:TDO:TCK:TMS may be the pin ID (0 <= id <= 7) or string value.

allowed values are:

value	ID
TXD	0
RXD	1
RTS	2
CTS	3
DTR	4
DSR	5
DCD	6
RI	7

Writing to an arbitrary address in flash memory¶

With FPGA using an external SPI flash (xilinx, lattice ECP5/nexus/ice40, anlogic, efinix) option -o allows one to write raw binary file to an arbitrary adress in FLASH.

Using an alternative directory for spiOverJtag¶

By setting OPENFPGALOADER_SOJ_DIR it’s possible to override default spiOverJtag bitstreams directory:

export OPENFPGALOADER_SOJ_DIR=/somewhere
openFPGALoader xxxx

or

OPENFPGALOADER_SOJ_DIR=/somewhere openFPGALoader xxxx