SAM4S_EEFC: Report FRDY=0 briefly after command write#198
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msarehn wants to merge 1 commit intorenode:masterfrom
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SAM4S_EEFC: Report FRDY=0 briefly after command write#198msarehn wants to merge 1 commit intorenode:masterfrom
msarehn wants to merge 1 commit intorenode:masterfrom
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The EEFC model previously always returned FRDY=1 in the status register. Firmware (e.g. ASF's efc_perform_read_sequence running from RAM) polls EEFC_FSR waiting for the FRDY=0 transition that indicates the flash controller has accepted a command. Without this transition the firmware spins forever. Set a flashBusy flag on command write and return FRDY=0 on the first subsequent status read, then FRDY=1 on the next read. This matches real hardware behaviour where FRDY briefly goes low. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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The EEFC model previously always returned FRDY=1 in the status register. Firmware (e.g. ASF's efc_perform_read_sequence running from RAM) polls EEFC_FSR waiting for the FRDY=0 transition that indicates the flash controller has accepted a command. Without this transition the firmware spins forever.
Set a flashBusy flag on command write and return FRDY=0 on the first subsequent status read, then FRDY=1 on the next read. This matches real hardware behaviour where FRDY briefly goes low.
Note
This is part of a larger effort to properly emulate SAM4E-based devices. I'll create some more PRs related to that; this note applies to all of them so I'll only put it here.
We are in need of SAM4E support in renode. The SAM4S support means it's mostly there, just some fixes here and there. Now I'm not very well versed in emulator development, so I've had Claude have a crack at it while looking at the datasheet and observing our firmware running in renode. It's working pretty well now, but the code is all AI-generated. I'm not sure what your stance on this is; it certainly needs review from someone knowledgable in the area. I've glanced over the code and I think it's okay-ish from my POV. No tests though; and I don't know if you require them.
In any case, we'd be happy to contribute the changes back upstream.