Hi Ian,
psram APS6404 must return ID 0x5D
BusPirate5-firmware/src/psram.c at main · x893/BusPirate5-firmware · GitHub at
line 13
i use latest pico-sdk from github
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Yes. The RP2350 should send command 0x9F and then read 6 bytes to get the ID. Instead, Rp2350 sends 0xff (red arrow).
for (size_t i = 0; i < 7; i++)
{
qmi_hw->direct_tx = (i == 0 ? PSRAM_CMD_READ_ID : PSRAM_CMD_NOOP);
If I manually change it to 0x00 or anything, still the output is 0xff. This is why my chip doesn’t answer with the ID.
Looks very strange. I havn’t LA but may be you can check PSRAM exchange on any other RP2350 boards ? Not on BP.
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