On Mon, Jun 20, 2011 at 6:14 PM, Øyvind Harboe <oyvind.har...@zylin.com> wrote: > (..) I would dearly like to see SWD done before > opening the floodgates to GPIO and other serial protocols.
SWD is packed-based half-duplex bus that defines TRN operation for bus direction change and buffers reconfiguration. There is no SWD without bitbanging the pins responsible for that TRN switch. It can be implemented per-interface in a source code, or it can be more general and bring even more use to existing code/hardware. The main reason for writing the bitbang was driving RnW pin that is responsible for TRN bus operation. This RnW can be implemented as one bit, or as bitmask, and even more bitmask that require setting one bits high and other bits low. This is must-have for transport other than JTAG. I will not hardcore this functionality only for one interface, if it can be used for all others with even more elegant solution, because I don't like this approach and I find it too much in current source code - if it was already there I would not have to write it from scratch! With presented signal/bitbang API it is possible to easily create other transports using smart interfaces, I bet even JTAG-only interfaces will score, and it is totally backward compatibile. It will be possible to quickly write custom TCL scripts that will provide lots of more new features than hardcoding them for some specific solution with specific hardware. Do you need anything more? Just let me know and give some time! :-) Best regards! :-) Tomek -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.info _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development
