Hello, while trying to implement the "remote sleep" portion of the OpenOCD remote_bitbang protocol, I noticed a somewhat serious design issue: SWD and sleep commands cannot be implemented at the same time, because they overlap:
- SWD uses d,e,f,g for setting pin state - sleep uses d,D for microsecond and millisecond sleep, respectively doc/manual/jtag/drivers/remote_bitbang.txt makes no mention of this conflict, so I guess it hasn't been noticed/considered. I'm not sure how "set in stone" the remote_bitbang protocol is, but I think it would be nice to resolve this issue in the long run. Idea 1: - Change the sleep commands to 'S' for 1 ms, 's' for 1 µs - Document that 'D' and 'd' as deprecated aliases - Switch the remote_bitbang driver in OpenOCD to 'S' and 's' Unfortunately that's a breaking change, because existing adapter-side implementations of the protocol will have to implement the s,S commands to keep working with newer OpenOCD. Idea 2: - Accept this unfortunate state of affairs, and document that SWD and remote sleep cannot be used at the same time - Enforce this in the OpenOCD driver as well I'm leaning towards idea 1, even though it may break some setups in the short term. Fortunately, the remote sleep commands haven't been part of an OpenOCD release yet, AFAICT. Let me know what you think! --- Best regards, jn
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