CCS :: View topic - Problem 24FJ256GB110 and 25LC256

CCS C Software and Maintenance Offers

FAQ

Official CCS Support

Profile Log in to check your private messages Log in

CCS does not monitor this forum on a regular basis.

Please do not post bug reports on this forum. Send them to CCS Technical Support

Problem 24FJ256GB110 and 25LC256

CCS Forum Index -> General CCS C Discussion

View previous topic :: View next topic

Author

Message

microlo75

Joined: 13 Apr 2010
Posts: 23

Problem 24FJ256GB110 and 25LC256

Posted: Wed Oct 06, 2010 10:34 am

Reply with quote

Hello,
I have this problem using a 24FJ256GB110 and 25LC256

Code:

#ifndef EEPROM_SELECT

#define EEPROM_SELECT PIN_D12
#define EEPROM_CLK PIN_G6
#define EEPROM_DI PIN_G8
#define EEPROM_DO PIN_G7

#endif

#define EEPROM_ADDRESS long int
#define EEPROM_SIZE 262144

void init_ext_eeprom() {
output_high(EEPROM_SELECT);
output_low(EEPROM_DI);
output_low(EEPROM_CLK);
}

BOOLEAN ext_eeprom_ready() {
BYTE cmd[1], i, data;

cmd[0] = 0x05; //rdsr opcode

output_low(EEPROM_SELECT);

for(i=1; i<=8; ++i) {
output_bit(EEPROM_DI, shift_left(cmd,1,0));
output_high(EEPROM_CLK); //data latches
output_low(EEPROM_CLK); //back to idle
}

for(i=1; i<=8; ++i) {
output_high(EEPROM_CLK); //data latches
shift_left(&data,1,input(EEPROM_DO));
output_low(EEPROM_CLK); //back to idle
}
output_high(EEPROM_SELECT);
return !bit_test(data, 0);
}

void write_ext_eeprom(EEPROM_ADDRESS address, BYTE data) {
BYTE cmd[4];
BYTE i;
BYTE wren;
wren=0x06;
cmd[0]=data;
cmd[1]=address;
cmd[2]=(address>>8);
cmd[3]=0x02;

// Wait until the eeprom is done with a previous write
while(!ext_eeprom_ready());

output_low(EEPROM_SELECT);
for(i=0; i<8; ++i)
{
output_bit(EEPROM_DI, shift_left(&wren,1,0));
output_high(EEPROM_CLK);
output_low(EEPROM_CLK);
}
output_high(EEPROM_SELECT);
output_low(EEPROM_SELECT);
for(i=0; i<32; ++i)
{
output_bit(EEPROM_DI, shift_left(cmd,4,0));
output_high(EEPROM_CLK);
output_low(EEPROM_CLK);
}
output_high(EEPROM_SELECT);
}

BYTE read_ext_eeprom(EEPROM_ADDRESS address) {
BYTE cmd[3];
BYTE i,data;
cmd[0]=address;
cmd[1]=(address>>8);
cmd[2]=0x03;

// Wait until the eeprom is done with a previous write
while(!ext_eeprom_ready());

output_low(EEPROM_SELECT);
for(i=0; i<24; ++i)
{
output_bit(EEPROM_DI, shift_left(cmd,3,0));
output_high(EEPROM_CLK);
output_low(EEPROM_CLK);
}
for(i=0; i<8; ++i)
{
shift_left(&data,1,input(EEPROM_DO));
output_high(EEPROM_CLK);
output_low(EEPROM_CLK);
}
output_high(EEPROM_SELECT);
return(data);
}

the program works, but sometimes there is an error in reading the EEPROM
how is it possible?

example:
about 10 times this routine 2-3 times only the right data!!

Code:

for(slot=0;slot<1000;slot++)
{
usb_cdc_putc(read_ext_eeprom(slot));
delay_us(300);
}

a few bytes are wrong!!!

I could not use the SPI ...
Embarassed

Embarassed

Thanks to all

PCM programmer

Joined: 06 Sep 2003
Posts: 21708

Posted: Wed Oct 06, 2010 12:20 pm

Reply with quote

I don't have the PCD compiler, so I can't help very much.
But, my suggestion is to prove that the SPI interface is the problem.
Change your test to the following:

Quote:

for(slot=0;slot<1000;slot++)
{
usb_cdc_putc((int8)slot);
delay_us(300);
}

This should display incrementing numbers from 0 to 255, several times.
If it fails, the problem is the CDC interface. If it works, the problem may
be in the SPI interface.

microlo75

Joined: 13 Apr 2010
Posts: 23

Solved
Posted: Fri Oct 08, 2010 11:25 pm

With SPI work !!!!! Thanks for reply bye

Display posts from previous:

	CCS Forum Index -> General CCS C Discussion	All times are GMT - 6 Hours
Page 1 of 1

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Powered by phpBB © 2001, 2005 phpBB Group