SPI EEPROM Help

[dustimv]

I am using a PIC18F4550 to write to a Microchip 25AA512 EEPROM. No matter what I send to the memory to be stored, I receive back a 0. This includes the reading of status registers. I have sent the data to another PIC and it read the data fine. I am not using any pull-up or pull-down resistors on any SPI lines. I have enclosed the code I am using. My software is MPLAB v7.60 and my CCS Compiler is PCH v3.249. Any help would be greatly appreciated.

#include <18F4550>
#fuses intrc_io,nowdt,noprotect,nolvp
#use delay(clock=8000000)
#use rs232(baud=9600)

#define cs pin_d2
#define wp pin_d3
#define hold pin_d4

int dat;

void main(){
setup_oscillator(osc_8mhz);
setup_spi(spi_master | spi_l_to_h | spi_clk_div_16);

//Setup Chip
output_high(hold);
output_high(wp);
output_high(cs);

delay_ms(500);

//Setup Send
output_low(cs);
spi_write(0x06);
output_high(cs);

delay_ms(500);

//Send Data
output_low(cs);
spi_write(0x02); //Write Command

spi_write(0x00); //16-bit Address
spi_write(0x00);

spi_write(0x04); //Data
output_high(cs);

delay_ms(500);

//Get Data
output_low(cs);
spi_write(0x03); //Read Command

spi_write(0x00); //16-bit Address
spi_write(0x00);

dat=spi_read(); //Data
output_high(cs);

if(dat==0x04){
output_high(pin_D1);
}

while(1){
}
}

[PCM programmer]

Look at Figure 1-2 on page 5 of the 25AA512 data sheet.
Notice on the left side of the timing diagram that it lists the two
SPI modes that the eeprom supports.
http://ww1.microchip.com/downloads/en/DeviceDoc/22021B.pdf

Now look at the table in ckielstra's post.
http://www.ccsinfo.com/forum/viewtopic.php?t=32040&start=5
What SPI mode is being specified by your setup_spi() statement below ?

[dustimv]

Thank you for the reply. I tried in both mode 0 and 3, still I read a zero back from the memory. I used both of the following lines of code.

setup_spi(SPI_MASTER | SPI_L_TO_H | SPI_XMIT_L_TO_H | SPI_CLK_DIV_16);
setup_spi(SPI_MASTER | SPI_H_TO_L | SPI_XMIT_L_TO_H | SPI_CLK_DIV_16);

Where did you find the command SPI_XMIT_L_TO_H? I can't find it anywhere in the compiler manual.

Any other ideas of what to try? Once again thank you for the reply, I appreciate the help.

[PCM programmer]

You may still have other problems with your driver, but the first step
is to setup the correct SPI mode, and also to make sure the connections
are correct. Example:

[dustimv]

I've checked the connections many times (twice more because of your post).

18F4550
-----------
SDO (C7) --> (P5) SI
SDI (B0) <-- (P2) SO
SCK (B1) --> (P6) SCK

CS (D2) --> (P1) CS

Which does bring me to a question, why did Microchip decide to make the SPI out the same pin as RS232 in. Anyway I'm still trying to figure out way I am always reading a zero from the store variable (dat). Thank you again for the quick response and suggestion.

[PCM programmer]