checksum of the first 7 entries of vector array for Cortex-M3 devices!

[reza_elc87]

Dear friends,

quoted from LPC1768 user mannual:
"The reserved Cortex-M3 exception vector location 7 (offset 0x 001C in the vector table)
should contain the 2's complement of the check-sum of table entries 0 through 6. This
causes the checksum of the first 8 table entries to be 0. The boot loader code checksums
the first 8 locations in sector 0 of the flash. If the result is 0, then execution control is
transferred to the user code."

How flash magic calculates the checksum of these entries nad its two's complement? I do the calculation, but mine is different than what flash magic offers.

[Andy Ayre]

Flash Magic handles this calculation for you automatically. There is no need to do it manually.

Andy