??? 03/01/07 13:30 Read: times |
#134018 - answer Responding to: ???'s previous message |
I will have my EEPROM connected to external address 0 through 7FFF.
the movx will send data to it one byte, at a time sequentially starting at address 0. How does that help program your EEPROM? The 805x can't execute code in XRAM. Directly. The code snippet I have provided is run when the system is being programmed. I will also make a switch that will redirect the PSEN to the correct location, so that my system can execute one of two pieces of code. That on the EEPROM, and the hardwired code that you already saw which programs the same EEPROM. Sure, I might be "ignorant" to some of you, but this is MY project, and I like to learn things. You never know, I might be one of the first few to invent an 8051 system with a built-in EEPROM programmer, where the EEPROM can be removed, and the CPU can stay in the system! |