Content originally posted in LPCWare by reza_elc87 on Tue Jun 30 01:55:12 MST 2015
Dear all,
Hello!
I have developed a C# program that can send a .hex file to the flash memory of LPC1768 using ISP. But the program does not work well. I know the problem is that it cannot verify a valid user code, because the checksum at location 7 of the vector table is incorrect.
this is the first 8 entries of my vector table:
:10000000 68020010 69010000 71010000 73010000 26
:10001000 75010000 77010000 79010000 [color=#f06]00000000[/color] 78
I know instead of those red zeros I need to put the two's complement of the checksum. The only problrm is that I do not know how to calculate the checksum and its two's complement.
Flash magic calculates it and gives:
E6F4FFEF
BUT HOW???