Flash Magic Forum

In-System Programming Support => ARM Cortex => Topic started by: reza_elc87 on June 30, 2015, 03:23:38 AM

Title: checksum of the first 7 entries of vector array for Cortex-M3 devices!
Post by: reza_elc87 on June 30, 2015, 03:23:38 AM
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.
Title: Re: checksum of the first 7 entries of vector array for Cortex-M3 devices!
Post by: Andy Ayre on July 01, 2015, 12:58:01 AM
Flash Magic handles this calculation for you automatically. There is no need to do it manually.

Andy