Problems with SPI

Hey guys,

I am working with PIC18F4620 micro in MPLAB with XC8 compiler below is the code I have written to initialize SPI. In the code i am trying to generate clock pluses by continuously sending 0xAA to the SPI output and I am simulating this code in PIC18 simulator, but I am not getting any signal on either of the pins (clk or the DO) and similarly I am also not getting any signal on the IC too. In simulation it is stuck at SSPSTAT –> BF waiting for it to go high and even if I set the flag high in simulation manually it still won’t generate any clock signal.                   There must be some silly mistake that I might have made please have a look.

 

Code

 

 

#include <xc.h>

#include <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <math.h>

#include <pic18f4620.h>

 

 

// PIC18F4620 Configuration Bit Settings

 

// CONFIG1H

#pragma config OSC = HSPLL      // Oscillator Selection bits (HS oscillator, PLL enabled (Clock Frequency = 4 x FOSC1))

#pragma config FCMEN = OFF      // Fail-Safe Clock Monitor Enable bit (Fail-Safe Clock Monitor disabled)

#pragma config IESO = OFF       // Internal/External Oscillator Switchover bit (Oscillator Switchover mode disabled)

 

// CONFIG2L

#pragma config PWRT = ON        // Power-up Timer Enable bit (PWRT enabled)

#pragma config BOREN = ON       // Brown-out Reset Enable bits (Brown-out Reset enabled and controlled by software (SBOREN is enabled))

#pragma config BORV = 3         // Brown Out Reset Voltage bits (Minimum setting)

 

// CONFIG2H

#pragma config WDT = OFF        // Watchdog Timer Enable bit (WDT disabled (control is placed on the SWDTEN bit))

#pragma config WDTPS = 32768    // Watchdog Timer Postscale Select bits (1:32768)

 

// CONFIG3H

#pragma config CCP2MX = PORTC   // CCP2 MUX bit (CCP2 input/output is multiplexed with RC1)

#pragma config PBADEN = OFF     // PORTB A/D Enable bit (PORTB<4:0> pins are configured as digital I/O on Reset)

#pragma config LPT1OSC = OFF    // Low-Power Timer1 Oscillator Enable bit (Timer1 configured for higher power operation)

#pragma config MCLRE = ON       // MCLR Pin Enable bit (MCLR pin enabled; RE3 input pin disabled)

 

// CONFIG4L

#pragma config STVREN = OFF     // Stack Full/Underflow Reset Enable bit (Stack full/underflow will not cause Reset)

#pragma config LVP = OFF        // Single-Supply ICSP Enable bit (Single-Supply ICSP disabled)

#pragma config XINST = OFF      // Extended Instruction Set Enable bit (Instruction set extension and Indexed Addressing mode disabled (Legacy mode))

 

// CONFIG5L

#pragma config CP0 = OFF        // Code Protection bit (Block 0 (000800-003FFFh) not code-protected)

#pragma config CP1 = OFF        // Code Protection bit (Block 1 (004000-007FFFh) not code-protected)

#pragma config CP2 = OFF        // Code Protection bit (Block 2 (008000-00BFFFh) not code-protected)

#pragma config CP3 = OFF        // Code Protection bit (Block 3 (00C000-00FFFFh) not code-protected)

 

// CONFIG5H

#pragma config CPB = OFF        // Boot Block Code Protection bit (Boot block (000000-0007FFh) not code-protected)

#pragma config CPD = OFF        // Data EEPROM Code Protection bit (Data EEPROM not code-protected)

 

// CONFIG6L

#pragma config WRT0 = OFF       // Write Protection bit (Block 0 (000800-003FFFh) not write-protected)

#pragma config WRT1 = OFF       // Write Protection bit (Block 1 (004000-007FFFh) not write-protected)

#pragma config WRT2 = OFF       // Write Protection bit (Block 2 (008000-00BFFFh) not write-protected)

#pragma config WRT3 = OFF       // Write Protection bit (Block 3 (00C000-00FFFFh) not write-protected)

 

// CONFIG6H

#pragma config WRTC = OFF       // Configuration Register Write Protection bit (Configuration registers (300000-3000FFh) not write-protected)

#pragma config WRTB = OFF       // Boot Block Write Protection bit (Boot Block (000000-0007FFh) not write-protected)

#pragma config WRTD = OFF       // Data EEPROM Write Protection bit (Data EEPROM not write-protected)

 

// CONFIG7L

#pragma config EBTR0 = OFF      // Table Read Protection bit (Block 0 (000800-003FFFh) not protected from table reads executed in other blocks)

#pragma config EBTR1 = OFF      // Table Read Protection bit (Block 1 (004000-007FFFh) not protected from table reads executed in other blocks)

#pragma config EBTR2 = OFF      // Table Read Protection bit (Block 2 (008000-00BFFFh) not protected from table reads executed in other blocks)

#pragma config EBTR3 = OFF      // Table Read Protection bit (Block 3 (00C000-00FFFFh) not protected from table reads executed in other blocks)

 

// CONFIG7H

#pragma config EBTRB = OFF      // Boot Block Table Read Protection bit (Boot Block (000000-0007FFh) not protected from table reads executed in other blocks)

 

 

 

#define rs   PORTDbits.RD6   //LATBbits.LB6

#define en   PORTDbits.RD7   //LATBbits.LB7

#define _XTAL_FREQ 40000000

 

#define le PORTDbits.RD4 //bus bar control

#define watch 0b00000001

#define drain_valve 0b10000000

#define cal_led 0b01000000

 

#define level_sw PORTEbits.RE2

 

#define CS_PIN         PORTCbits.RC2 //3     // Chip Select

#define TRIS_CS_PIN    TRISCbits.TRISC2

#define DIN_PIN        PORTCbits.RC4     // Data in

#define TRIS_DIN_PIN   TRISCbits.TRISC4

#define DOUT_PIN       PORTCbits.RC5 //6    // Data out

#define TRIS_DOUT_PIN  TRISCbits.TRISC5

#define SCK_PIN        PORTCbits.RC3 //5    // Clock

#define TRIS_SCK_PIN   TRISCbits.TRISC3

 

void config_spi(void);

unsigned char write_spi(unsigned char mybyte);

unsigned char read_spi(void);

 

void main(){

TRISB =0x00;                        // lcd 0-7

TRISD =0x00;                        // D6, D7

TRISC = 0b10010011;

TRISE =0b101;

PORTEbits.RE1 = 0;

PORTB =0x00;

PORTD =0x00;

 

CS_PIN        = 1;     // Chip Select

 

ADCON0 = 0x00;

ADCON1 = 0b00001111;               // all pins digital

 

unsigned char data=’a’;

config_spi();

 

 

while(1) write_spi(0xAA);

}

 

 

void config_spi(void){

TRIS_CS_PIN   = 0;

TRIS_DIN_PIN  = 1;

TRIS_DOUT_PIN = 0;

TRIS_SCK_PIN  = 0;

SSPSTAT =0b10000000;

//SSPCON1 =0x22;

SSPCON1 = 0b00100010;

SSPADD =0x00;

CS_PIN        = 0;     // Chip Select

}

 

unsigned char write_spi(unsigned char mybyte){

SSPCON1bits.WCOL =0;

PIR1bits.SSPIF =0;

SSPBUF = mybyte;

//while(!SSPSTATbits.BF);

while(!PIR1bits.SSPIF);

return SSPBUF;

}

 

unsigned char read_spi(void){

while(!SSPSTATbits.BF);

return SSPBUF;

}