[Libre-soc-dev] daily kan-ban update 21sep2020

[Luke Kenneth Casson Leighton]

JTAG 2 DMI interface written, based instead on Staf Chips4Makers TAP
code, well written, understandable enough to drop a DMI FSM on it.

quick unit test shows that c4m jtag IDCODE csn be read, dmi interface
works and wishbone works too.

tomorrow i will link into litex sim, i am not sure whether to replace
the DMI debug code already in place, it was real handy.

also drop in JTAG into ls180soc and see how that goes.

l.