Cannot use SPI flash in user mode

openXC7 / xc7k325t-blinky-nextpnr

BSD 3-Clause "New" or "Revised" License

43 stars 9 forks source link

Cannot use SPI flash in user mode #23

Open jrrk2 opened 2 years ago

jrrk2 commented 2 years ago

I just noticed there isn't a way to connect SCK to the STARTUP primitive in our current flow. This will mean we cannot at the moment use SPI memory in the user design the way picosoc (conventional version) does it.

ERROR: Unable to place cell 'startup', no Bels remaining of type 'STARTUPE2'

unbtorsten commented 2 years ago

Where would you locate the lack of support? Does this concern nextpnr, prjxray (fuzzers), ...?

hansemro commented 2 years ago

prjxray has fuzzer for cfg (which contains BSCAN, STARTUP, and others): prjxray/fuzzers/038-cfg/

However, I noticed that CFG_CENTER_MID tile and its sites are not defined/used in arch-defs.

I have been trying to understand arch-defs and how it manages tiles/sites in this branch, but there are some options in xc/common/cmake/project_ray.cmake I don't fully understand.