[Libre-soc-dev] [Libre-soc-bugs] [Bug 503] New: Create new repo for gdb-adaptor program

Luke Kenneth Casson Leighton lkcl at lkcl.net
Sun Sep 27 01:02:05 BST 2020

On Sat, Sep 26, 2020 at 4:12 PM Luke Kenneth Casson Leighton
<lkcl at lkcl.net> wrote:

> *now* with the openocd svf command tested, i can go back to the litex
> sim.py, confident that the openocd side is working (and the C4M JTAG
> TAP adapter) and investigate why that's not responding with the
> correct DMI responses.

found the issue, it was a comb instead of a sync, where the DMI
protocol needs a 1 clock delay between req(uest) and ack(knowledge).
changing to sync created that 1 clock delay, and now C4M JTAG TAP is
confirmed working, i can get at the DMI interface via JTAG.

tomorrow i will try wishbone.


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