EE_PROM addressing above addr 255

[Phil G]

The PIC18F6720 has 1K of data EEPROM; How can I address it if the CCS functions for reading and writing take only an 8-bit address?

Phil G
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This message was ported from CCS's old forum
Original Post ID: 144514669

[Tomi]

The trivial solution is:
void MyWrite_eeprom(unsigned long addr,char data)
{
#byte addrL = addr
#byte addrH = addr+1

*0x0FAA = addrH; // load upper addr byte
Write_eeprom(addrL,data);
}

char MyRead_eeprom(unsigned long addr)
{
#byte addrL = addr
#byte addrH = addr+1

*0x0FAA = addrH; // load upper addr byte
return read_eeprom(addrL);
}

:=The PIC18F6720 has 1K of data EEPROM; How can I address it if the CCS functions for reading and writing take only an 8-bit address?
:=
:=Phil G
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This message was ported from CCS's old forum
Original Post ID: 144514670

[Woody]

Although the CCS documentation and help file state that the parameter to the EEPROM library functions is an int, a test with PCWH version 3.158 shows that it is correctly using a long parameter for the 18F6720.

Apparently the documentation has not caught up with the compiler capabilities.


#include <18F6720.h>

void main (void)
{
long a = 700;

write_eeprom (a, 55 );

}
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This message was ported from CCS's old forum
Original Post ID: 144514691

[rret]

:=The trivial solution is:
:=void MyWrite_eeprom(unsigned long addr,char data)
:={
:=#byte addrL = addr
:=#byte addrH = addr+1
:=
:=*0x0FAA = addrH; // load upper addr byte
:=Write_eeprom(addrL,data);
:=}
:=
:=char MyRead_eeprom(unsigned long addr)
:={
:=#byte addrL = addr
:=#byte addrH = addr+1
:=
:=*0x0FAA = addrH; // load upper addr byte
:=return read_eeprom(addrL);
:=}
:=
:=:=The PIC18F6720 has 1K of data EEPROM; How can I address it if the CCS functions for reading and writing take only an 8-bit address?
:=:=
:=:=Phil G

I understand where you get the 0x0FAA, but what do you pass in for the "addr" parameter when you call MyWrite_eeprom()?
(Say you wish to write a byte to the first eeprom "cell".)
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This message was ported from CCS's old forum
Original Post ID: 144516254