| ??? 10/18/08 09:13 Read: times |
#159180 - EPROM has special write-procedures Responding to: ???'s previous message |
Jorge Lopes said:
I already had problens with a paralel eeprom. What, exactly, did you try? What problems, precisely, did you have? Obviously, people cannot tell you where you are going wrong if they don't know exactly what you're doing! Have you looked at the Datasheet for the device to check the required programming procedure? Richard Erlacher said:
EEPROM has special write-procedures beyond what is done with a simple MOVX instruction. Yes - and I think that's true of both Electrically Eraseable and UV Eraseable PROMs? A PROM is not just a conventional Read-Write memory in which the write function can simply be disabled - the operation is basically Read-Only, to which a programming facility has been added. That's probably why the process of getting the data into an EPROM (whether UV-EPROM or E-EPROM) is usually referred to as Programming - and not just as "writing" The Datasheet for the device will describe the procedure required for programming - often called the "algorithm". In an 8051 application, programming will include the use of MOVX - but there's more to it than that! As I've said, what he wants is a some sort of non-volatile RAM. Yes, I think so too! He might very well be able to "get by", in this case, with a "4.5-volt" battery and a few diodes, primitive as that is, as a supply to a CMOS SRAM. Quite probably! |
