I'm still trying to figure out this oscilloscope (dso nano) which I think needs a firmware update. I'm looking at a log of CLK from the voltage divider connected to my raspberry pi. The chart goes off the display and it says the peak-to-peak voltage is 33.6V . It goes off the display in both the positive and negative directions. A raspberry pi usually produces no more than 5V, so this is some electrical thing. I don't know a lot about electronics, but they're full of noise and stuff. On Tue, Apr 5, 2022, 7:15 AM Undiscussed Horrific Abuse, One Victim of Many <gmkarl@gmail.com> wrote:
On Tue, Apr 5, 2022, 7:02 AM Undiscussed Horrific Abuse, One Victim of Many <gmkarl@gmail.com> wrote:
notes: in the flasher source, it's designed for more than one interface, and use of the lpc chip is guarded by this: uint8_t lpc_test(void) { nibble_hw_init();
FRAME is driven high for 1us and then allowed to drop for 1us.
lpc_init();
calls nibble_init(): INIT is briefly dropped and then raised. CLK is raised. FRAME is raised. calls nibble_write(0): DATA lines are set high. calls clock_cycle() 24 times. The code for clock_cycle drops CLK then immediately raises it.
It goes on with more port writes. I may have made an error in transcribing the above.
I'm guessing the clock is happening faster than I have my oscilloscope set. Maybe I can spend some time learning it better and see the 1us FRAME behavior.
if (lpc_read_address(0xFFFFFFFF)==-1) return 0;
return 1; }
flashrom itself doesn't seem to care about that check (although I haven't looked in the source): it just probes for a bunch of chips anyway.
so I guess the thing to do would be to look for the first lines that are engaged, and see where failure starts.