eeprom reading

[Allen]

Hi guys,
I have following code to test my eeprom data with 16f877 (mplab 6.2).
However, I cann't read the data from the eeporm window, all the data shown are FF.
Do i have to make any setting in order to config the eeprom window show the right address range (0x2100 - 21FF)??

#include <16F877.h>
#device ICD=TRUE
#fuses HS, NOWDT, NOPROTECT, NOLVP
#use delay(clock = 4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)

void main()
{
int i;
byte temp;
while(1){
printf("In while loop\r");
output_low(PIN_B1);
delay_ms(1000);
output_high(PIN_B1);


temp = read_eeprom(0x2100);
printf("2100 data is \%u", temp);
}
}
#ROM 0x2100 = {
0x18, //addr offset: 00
0x00, //addr offset: 01
0x90, //addr offset: 02
}

Also,is it reading /writting data from sram is fater than eeprom, if so, what is the address range for sram.
what about wiritting data into program memory? is it faster than sram, eeprom, and how can i insert data in program memory (i mean data not the source code)

thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 144517440

[PCM programmer]

Here is a demo program that you should try.

When you program the HEX file into the PIC, make sure that
your programmer is enabled for writing to EEPROM.

On many programmers (such as PicStart-Plus with MPLAB),
there is a separate "check box" that must be selected
to allow writing data to the internal EEPROM.

If you do that, the following program should work.

<PRE>
//-------------------------------------------------------------
// INCLUDE FILES
<BR>
#include "16f877.h"
<BR>
//-------------------------------------------------------------
// COMPILER DIRECTIVES
<BR>
#fuses HS, NOWDT, NOPROTECT, PUT, BROWNOUT, NOLVP
#use Delay(Clock=8000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
<BR>
#rom 0x2100 = {'H','E','L','L','O',' ','T','H','E','R','E'}
<BR>
//============================================================

main()
{
char value;
char addr;
<BR>
// Read back the internal eeprom and display the results.
<BR>
for(addr = 0; addr < 11; addr++)
{
value = read_eeprom(addr);
printf("\%x ", value);
}
printf("\n\r");
<BR>
while(1);
}
</PRE>
___________________________
This message was ported from CCS's old forum
Original Post ID: 144517441