I have made a simple pcb for the lpc11u24, and can copy a
firmware file to it via USB MSC, but the code never runs.
From trying different combinations of high and low on P0_1
and P0_3, it would seem that the processor is finding my
user code to be invalid. Specifically, if P0_1 and P0_3 are
both high at reset, the device shows up as a USB drive
instead of running my code.
Section 20.7 of the user's manual says that user code is
valid if the 32-bit sum of the first eight 32-bit words
of memory is zero. The mbed compiler seems to put the
proper checksum into location 7 to make this true, so I
am baffled about why my code isn't running. The first
eight words are these:
10001000
00000219
00000233
00000221
00000223
00000225
00000227
e324efff
Does anybody have any other ideas for me to check?
Thanks,
Ralph
I have made a simple pcb for the lpc11u24, and can copy a firmware file to it via USB MSC, but the code never runs. From trying different combinations of high and low on P0_1 and P0_3, it would seem that the processor is finding my user code to be invalid. Specifically, if P0_1 and P0_3 are both high at reset, the device shows up as a USB drive instead of running my code.
Section 20.7 of the user's manual says that user code is valid if the 32-bit sum of the first eight 32-bit words of memory is zero. The mbed compiler seems to put the proper checksum into location 7 to make this true, so I am baffled about why my code isn't running. The first eight words are these: 10001000 00000219 00000233 00000221 00000223 00000225 00000227 e324efff
Does anybody have any other ideas for me to check?
Thanks, Ralph