16 bit hexadecimal checksum calculator online

How is this handled? My guess is that each program memory location is allocated 16 bits in the hex file, and the top 2 or 4 bits are zero. The program space is 12 or 14 bits wide, instead of the 8 or 16 bits that the hex file is designed around. The PIC doesn't fit with the standard hex file format in several respects. If the checksum is something different, you'll need to try some other ways of combining the data to see whether you can come up with the same number. If the tool displays a checksum of 0圎01, then you know that's how the checksum is calculated, although I would try one or two other short programs just to make sure. The bottom 12 bits of that value are 3585 or 0圎01. The NOP at 0x0000 is 0 so there's nothing to add. So you can calculate the 12-bit checksum of those values by multiplying 0xFFF (4095) by 511, the number of blank locations. The rest of the program memory will be blank. Say your program consists of just a NOP (opcode 0x000) at address 0. The program memory in the PIC12F508 has 512 locations, each containing a 12-bit opcode.

I suggest you write a small program (just a few instructions), load it into an emulator, view the program memory, add all the word values together, and see if the result matches the checksum reported by the tool. It may be an exclusive-OR of the data, rather than a sum. It should be calculated on the whole program address space, with words that are not defined in the hex file being assumed to be all 1-bits, so that it will match the checksum obtained by reading the program memory and adding all the words together. If it's a 16-bit checksum, or a 12-bit or 14-bit checksum in the case of a PIC, it's probably the bottom bits of the sum of the program words. If it's an 8-bit checksum, it's usually the bottom eight bits of the sum of the data bytes. I can't tell you how any particular program calculates the checksum, but it's not going to be complicated.

16 bit hexadecimal checksum calculator online