spi data transfer problem

harshadgami — Mon, 09 May 2016 04:51:46 GMT

hello sir ,

i have used TWR-K20D72 freescale board. in this board i connect CAT25256 (EPROM). i have write data in eeprom memory but faced a problem because of my initilization problem also problem of data write and read.

my system clock frequency is 72mhz. i have set 1 mhz baud rate for spi and how to set it.

#include "common.h"

/* ================== EEPROM command macros ==================*/

#define WR_EN 0x06

#define WR_DI 0x04

#define RD_SR 0x05

#define WR_SR 0x01

#define READ 0x03

#define WRITE 0x02

#define MAX_PAGE_SIZE 64

#define CS_ENABLE GPIOD_PCOR |= (1 << 4)

#define CS_DISABLE GPIOD_PSOR |= (1 << 4)

#define CS_GPIO_CONFIG PORTD_PCR4 = PORT_PCR_MUX(0x1)

#define CS_DIR_OUT GPIOD_PDDR |= (1 << 4)

#define PCS0 0x1

#define DATA 'A'

#define ADDRESS 0x0000

/*=============== Functions declaration ====================*/

void spi_init(void);

char spi_send(char);

void delay(void);

void isDeviceReady(void);

void my_delay(void);

void eeprom_write(int address);

char eeprom_read(int address);

static char tmp;

///please write a correct spi_send byte function

char spi_send(char Txfifo)

{

SPI0_MCR &= ~SPI_MCR_HALT_MASK; //Start Transfer

SPI0_PUSHR = Txfifo;

SPI0_MCR |= SPI_MCR_HALT_MASK; //Stop Transfer

while(!(SPI0_SR & SPI_SR_TCF_MASK)); //Wait for transfer complete flag

SPI0_MCR |= SPI_MCR_CLR_TXF_MASK;

tmp=SPI0_POPR;

return tmp;

}

/////please write a correct spi_receive byte function

uint8_t spi_receive()

{

SPI0_MCR |= SPI_MCR_CLR_RXF_MASK;

SPI0_SR |= SPI_SR_TCF_MASK;

SPI0_PUSHR = 0x00;

//while (!(SPI0_SR & SPI_SR_TCF_MASK)) {}

return ((char)SPI0_POPR);

}

void spi_init(void)

{

SIM_SCGC5 |= SIM_SCGC5_PORTD_MASK; //Turn on clock to D module

SIM_SCGC6 |= SIM_SCGC6_SPI0_MASK; //Enable SPI0 clock

CS_GPIO_CONFIG; // Configured GPIO

CS_DIR_OUT; // Select CS pin as Output direction

CS_DISABLE; // Disable CS

PORTD_PCR1 = PORT_PCR_MUX(0x2); //Set PTC5 to mux 2 [SPI0_SCK]

PORTD_PCR2 = PORT_PCR_MUX(0x2); //Set PTC6 to mux 2 [SPI0_MOSI]

PORTD_PCR3 = PORT_PCR_MUX(0x2); //Set PTC7 to mux 2 [SPIO_MISO]

SPI0_MCR |= (SPI_MCR_MSTR_MASK | //DSPI is in Master mode.

SPI_MCR_HALT_MASK); //Stop transfers

SPI0_MCR &= ~SPI_MCR_PCSIS(1);

// how to set 1 mhz???please write a correction

SPI0_CTAR0 |= (SPI_CTAR_PBR(3) | SPI_CTAR_BR(0x04));

//Frame Size = 8 bits

SPI0_CTAR0 &= ~SPI_CTAR_FMSZ(7);

SPI0_MCR &= ~SPI_MCR_MDIS_MASK; //Enable module

}

/* ============ Send Write Enable Command =========== */

void write_enable(void)

{

CS_ENABLE;

my_delay();

spi_send(WR_EN); // Send Write Enable Command

my_delay();

CS_DISABLE;

}

/* ============ Send Write Disable Command =========== */

void write_disable(void)

{

CS_ENABLE;

my_delay();

spi_send(WR_DI); // Send Write Enable Command

my_delay();

CS_DISABLE;

}

void eeprom_write(int address)

{

// Send Write Enable Comamnd

write_enable();

// Sequence of Write Command

CS_ENABLE;

my_delay();

spi_send(WRITE); // Send writing command to EEPROM

spi_send(address >> 8); // Send Writing address

spi_send(address); // Send LSB Address

spi_send(DATA);

my_delay();

// Disable Chip Selection Pin

CS_DISABLE;

// Delay for processing Write byte into EEPROM location

// Disable Write

write_disable();

my_delay();

}

char eeprom_read(int address)

{

static char temp;

// Enable Chip selection pin

CS_ENABLE;

my_delay();

spi_send(READ); // Send Read command

spi_send(address >> 8); // Send address from where to read form EEPROM

spi_send(address); // Send LSB Address

temp=spi_receive(0xff);

CS_DISABLE;

my_delay();

CS_ENABLE;

my_delay();

// Disable Chip selection pin

CS_DISABLE;

return temp;

}

void my_delay(void)

{

volatile uint32_t delayTicks = 2000;

while(delayTicks--)

{

__asm("NOP");

}

void delay(void)

{

volatile uint32_t delayTicks = 2000000;

while(delayTicks--)

{

__asm("NOP");

}

void main()

{

char data;

spi_init();

delay();

// Write multiple bytes into EEPROM

eeprom_write(ADDRESS);

// Read multiples bytes from EEPROM

data=eeprom_read(ADDRESS);

while(1);

}

Re: spi data transfer problem

Alice_Yang — Mon, 09 May 2016 07:31:33 GMT

Hello harshad,

Are you sure the the core/system clock is 72M?

I recommend you create on PE project ,then add the component of SPI,

there is demo code about SPI and the easy configuration :

About how to find these demos you can refer to this DOC:

How to Start CAN Module Development on KDS v3.2.0 + Processor Expert (this is the same with CW)

Hope it helps

Alice

Re: spi data transfer problem

harshadgami — Mon, 09 May 2016 09:08:03 GMT

sir, i am currently used IAR embedded workbatch software.

In this how i can set 1MHZ clock frequency.

how SPI0_PUSH & SPI0_POPR worked???

Re: spi data transfer problem

Alice_Yang — Tue, 10 May 2016 02:14:51 GMT

Hello Harshad,

Please refer to the calculation formula of Reference manual

Have a great day,
Alice

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