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10/17/08 02:45
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 		 #159125 - MOVX doesn't work for writing.
Hi,

I use AT28C64B EPROM.
I can read data from EPROM by using movx (address=5000h), but i can't write it.

mov DPTR,#5000h
mov A,#05h
movx @DPTR,A

-Is there anything wrong?
-Do I have to erase all data before writing?
Thx.


List of 41 messages in thread
TopicAuthorDate
MOVX doesn't work for writing.            01/01/70 00:00      
   It's a read-only memory            01/01/70 00:00      
      EEPROM            01/01/70 00:00      
         RAM-EPROM            01/01/70 00:00      
            That wouldn't be an EEPROM.            01/01/70 00:00      
            Look at Ferro-electric memory            01/01/70 00:00      
         Not wrong.            01/01/70 00:00      
            An EEPROM is an EPROM            01/01/70 00:00      
               Technically, but not in common usage of the term.            01/01/70 00:00      
                  Common use != Definition            01/01/70 00:00      
               Not quite ...            01/01/70 00:00      
                  No, it's not            01/01/70 00:00      
                  A datasheet that actually calls it a "UVEPROM"            01/01/70 00:00      
                     OK ... I stand corrected ...            01/01/70 00:00      
                        A link with EPROM <= EEPROM            01/01/70 00:00      
                        Not that generic!            01/01/70 00:00      
                           Magnetic core memory            01/01/70 00:00      
                           it is SERIAL EEPROM            01/01/70 00:00      
                              UVEPROM?            01/01/70 00:00      
                                 I think a part number would be the solution            01/01/70 00:00      
                                    Symmetric speed too.            01/01/70 00:00      
                           ta paidia paizei !!!            01/01/70 00:00      
            EEPROM implies EPROM            01/01/70 00:00      
               Today, it's the other way round.            01/01/70 00:00      
                  assumption < implication            01/01/70 00:00      
                  You missed the point!            01/01/70 00:00      
                     As one of my old tutors used to say...            01/01/70 00:00      
         Let's not confuse things further            01/01/70 00:00      
            You have also missed the point            01/01/70 00:00      
      Or...            01/01/70 00:00      
   Some Kind Like....            01/01/70 00:00      
      Non-Volatile Memory            01/01/70 00:00      
         or maybe the AT28C64B will work            01/01/70 00:00      
      You mean you want an NVRAM?            01/01/70 00:00      
   write eeprom            01/01/70 00:00      
      that may not be the problem            01/01/70 00:00      
         EPROM has special write-procedures            01/01/70 00:00      
   Check the write waveform timings!!!!!            01/01/70 00:00      
      How?            01/01/70 00:00      
         Source code to simulate MOVX...            01/01/70 00:00      
         Start with the datasheet ...            01/01/70 00:00      

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