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ReadWrite EEPROM in 89S8252

I got a code, and modified it to run..
But i can't seem to get the code correct.
it has to do with XDATA but i can't seem to get it right.

#include <AT898252.H>
#include "lcd.c"


BYTE ReadEEPROM(int addr)
{
	char EEdata;
	WMCON |= 0x08; // Enable EEPROM memory space

	EEdata = addr; // --> how do u write here?

	WMCON &= 0xF7; // Disable EEPROM memory space
	return(EEdata);
}

// To write a single byte to a location in EEPROM.

void WriteEEPROM(int addr, char EEdata)
{
	WMCON |= 0x08; // Enable EEPROM memory space
	WMCON |= 0x10; // Enable EEPROM memory write

	addr = EEdata; --> how do u write here?

	msdelay(15);
	WMCON &= 0xEF; // Disable EEPROM memory write
	WMCON &= 0xF7; // Disable EEPROM memory space
}


here's the assembly version..it worked..
but didn't manage to convert it into C.


WMCON DATA 96h ; watchdog and memory control register
EEMEN EQU 00001000b ; EEPROM access enable bit
EEMWE EQU 00010000b ; EEPROM write enable bit
WDTRST EQU 00000010b ; EEPROM RDY/BSY bit
ADDRESS EQU 10H
DATAS EQU 0AAH

; EEPROM read example.

;orl WMCON, #EEMEN ; enable EEPROM accesses
;mov dptr, #ADDRESS ; address to read
;movx a, @dptr ; read EEPROM
;xrl WMCON, #EEMEN ; disable EEPROM accesses

; EEPROM write example, utilizing fixed delay for write cycle.
; Delay is worst case (10 ms). Code for delay is not shown.
; Write is followed by verify (read and compare), but code to handle
; verification failure is not shown.


orl WMCON, #EEMEN ; enable EEPROM accesses
orl WMCON, #EEMWE ; enable EEPROM writes

mov dptr, #ADDRESS ; address to write
mov a, #DATAS ; data to write
movx @dptr, a ; write EEPROM

xrl WMCON, #EEMWE ; disable EEPROM writes
xrl WMCON, #EEMEN ; disable EEPROM accesses

Parents
  • "But _at_ doesn't seem to me to add any real convenience over standard C features unless you're pointer-phobic."

    It allows you to locate 'constant variables' in code space at known addresses without having to muck about with the linker.....

    "And it risks losing another thread to the complaint about how you can't use _at_ with initializers :)"

    .....but doesn't let you initialise them.

    What's the point of an uninitialised constant?

Reply
  • "But _at_ doesn't seem to me to add any real convenience over standard C features unless you're pointer-phobic."

    It allows you to locate 'constant variables' in code space at known addresses without having to muck about with the linker.....

    "And it risks losing another thread to the complaint about how you can't use _at_ with initializers :)"

    .....but doesn't let you initialise them.

    What's the point of an uninitialised constant?

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