Just for clarity I should add that the above experiments single stepping the BSL were done in the CCS debugger, allowing things like register change at any time. On thinking about it some more, turning off the LDOs (USB9 errata) might not actually be an issue on a real product with the processor running at a fair speed - the caps on the VUSB (3v3) should hold up long enough for the next couple of instructions to execute which turns the LDOs back on. So this *could* be a artifact of using the debugger. Though that said, when I just set it to run, and then paused execution, it was sitting in an infinite loop in the NOP after the LDO's were disabled. *Very strange* My next plan had been to try and modify the BSL to remove that errata fix (USB 9); which is deletion of a couple of lines of code. And change the XT2 strength from its default 3 to 0 which suits the 4MHz resonator.... and then try again using the debugger. The BSL seems to be a wrapper around a cut down of the MSP-Ware USB code, so in theory once that all gets running it should be much like the real application and enumerate properly. Any other advice though it most gratefully received. I had 10 uF on that 3v3 line and removed it. Looks like I better find some more 10 uF caps and get soldering at least as a first attempt.
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