I am Using PIC16f877a's SPI Protocol to program the 8051 IC.
My design is to Program the 89s51 one by one ie..Single byte at a time.
I will get the Address, Opcode from Serial Port(No intel Hex Format) and Programming the 89s51.
I Programmed the IC successfully and Tested it.
Here the Problem i cannot write a same location second time.
For Example:
I have written 0x0046--0xaa
If i Write the same location Second Time 0x0046---0x32.
The Location 0x0046 changed to 0x00...( 0x32 not written).
Is there any method to erase a Particular memory location?
Erasing all the contents will erase everything
but i need to edit some portion of a large program by modifying few memory locations only.
remaining content should be retained.
That particular memory location editing is not working. thats is my problem
The only way to modify a part of the content is to read the whole content into a temporary storage (I'd use an external serial eeprom e.g. 24Cxx, if there is not enough internal storage onchip of the PIC); perform the erase, and then write back the modified content.