Internal EEPROM.

[Nexus]

Hi. I’m currently doing an project with AT89S8352 microcontroller with Assembly language. I have learnt it and done some very simple code, up to this point however. I have tried to read and understand the internal EEPROM in the micro-controller, however I am not able to write a successful code to compile and see it working on a virtual simulation program (Proteus . I really would like your help to help me understand how to make a code to read and write into the internal EEPROM of the AT89S8352. This is what I have coded so far.

 

 

EECON DATA 96H ; watchdog and memory control register

EEMEN EQU 00001000B ; EEPROM access enable bit

EEMWE EQU 00010000B ; EEPROM write enable bit

EELD EQU 00100000B ; EEPROM page load enable bit

WRTINH EQU 00000001B ; EEPROM WRTINH bit

RDY EQU 00000010B ; EEPROM RDY/BSY bit

 

Read:

orl EECON, #EEMEN ; enable EEPROM accesses

mov dptr, #ADDRESS ; address to read

movx a, @dptr ; read EEPROM

xrl EECON, #EEMEN ; disable EEPROM accesses

 

Write:

orl EECON, #EEMEN ; enable EEPROM accesses

orl EECON, #EEMWE ; enable EEPROM writes

mov a, EECON ; get EEPROM status

anl a, #WRTINH ; check WRTINH

jz ERROR ; jump if inhibited

mov dptr, #ADDRESS ; address to write

mov a, #DATA ; data to write

movx @dptr, a ; write EEPROM

call DELAY_10_MS ; wait 10 ms

movx a, @dptr ; read EEPROM

cjne a, #DATA, ERROR; jump if data compare fails

xrl EECON, #EEMWE ; disable EEPROM writes

xrl EECON, #EEMEN ; disable EEPROM accesses

 

 

My question is, what is the ADDRESS in the Read code? Is the address meant for the micro-controller or EEPROM? If it’s meant for the EEPROM, what other addresses are there?

 

Is the ADDRESS in Read and Write the same address? If, they are different addresses, what are they?

 

What is the DATA ? What kind of data can be written? Would like an example of all possible data please.

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