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Problem with interface with 6264 ram

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mahm150

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Problem with interface 8052 with 6264 ram

WHEN WRITE TO 6264 RAM IN THE FIRST BYTE WRITE OK
BUT THE SECOND NOT WHY ?

mov R0,#00H
mov A,#022H //
movx @R0,A
CALL DELAY
mov R0,#01H
mov A,#0FFH
movx @R0,A
 

mahm150

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i try to read from look up table but the same here is my code
MOV DPTR,#ONEL
BEGIN :
MOVC A,@A+DPTR
movx @R0,A
CALL DELAY
CLR A
mov R0,#01H
mov A,#088H
movx @R0,A
ONEL:
DB 0FFH, 010H
and i will send the result in pic
 

btbass

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During a write, the data is latched on the rising edge of the WE (Write Enable) line. I can not see when you are doing this?

Have you looked at the timing waveforms on the data sheet?
 

mahm150

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If i understand the data must be valid when we is low and i know that the instruction movx do it if i miss understand tell me the correct
 

btbass

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You need to study the timing waveforms in the data sheet.
You change the data when WE is low and the data is latched in when WE goes high. You need to control the WE line and the OE line. Also the CS lines.
OE should be high during a write.
 

mahm150

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The instruction movx not controlled wr or rd pin in micro OR NOT
in data sheet the hased area what it mean

---------- Post added at 20:28 ---------- Previous post was at 20:25 ----------



---------- Post added at 20:36 ---------- Previous post was at 20:28 ----------

HOW TO CONTROL THE ALE PIN IN MICRO IT WORK WITH MOVX INSTRUCATION
 

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