If the sum value of the object file and the sum value at the time of writing do not match, the following factors are possible.
(1) When the method of calculating the sum value of the object file and the method of calculating the sum value of the writer are different.
The programmer's sum value calculation uses a simple addition method that ignores digit overflow. If the sum value calculation of the object file is complement calculation, it does not match the sum value of the writer, so please check the sum value calculation method of the object file.
(2) When the data size of the object file is smaller than the size of the flash memory
The programmer calculates the sum value within the range actually written to the flash memory. Normally, the sum value is calculated assuming that there is FF data for the part where there is no data in the object file. (If the buffer is cleared before loading the file)
(3) When the buffer is not cleared before loading the file
If you do not clear the buffer, some of the previously loaded contents may remain in the buffer memory and the sum values may not match.