LPC804 SPI INTERFACE

[Sathiya_T]

Hi,

Am using LPC804 developement board for SPI interface  with MCU IDE,  when using the registers TXDAT and RXDAT are configured then only the SCK is  verified  in digital oscilloscope. i cant to verify the SCK of transmit data using TXDAT.

[berlinraj]

SYSCON->SPI0CLKSEL=1<<11; //explain this code

[xiangjun_rong]

Hi,

As the following pin movable function, you can configure the SPI0 pin to a pad with SWM module.

I copy the Figure from UM11065.pdf

For example,in SPI master mode,  if you configure the

SWM->PINASSIGN2=0x04030201;

then SCK will output from PIO0_1

MOSI will output from PIO0_2,

MISO will input from PIO0_3;

SSEL0 will output to PIO0_4

In conclusion, pls check the SWM->PINASSIGN2 register to know the pin assignment of SPI

Note pls also check the section 8.5.12 PINENABLE 0 if the PIO0_x pin is multiplexed with analog function.

Hope it can help you

BR

XiangJun Rong

[Sathiya_T]

/* Initialize the SPI master with configuration. */

SYSCON->SYSAHBCLKCTRL0 |= (1<<11);
SYSCON->PRESETCTRL0 &=~(1<<11);
SYSCON->PRESETCTRL0 |=(1<<11);

SYSCON->SYSAHBCLKCTRL0 |= (1<<7);
SWM0->PINASSIGN_DATA[2] |= (0x1B)<<0;//port0-27
SWM0->PINASSIGN_DATA[2] |= (0x1A)<<8;//port0-26
SWM0->PINASSIGN_DATA[2] |= (0x1C)<<24;//PORT0-

/* Attach main clock to SPI0. */
CLOCK_Select(kSPI0_Clk_From_MainClk);

SPI0->DIV |=0X1D;
SPI0->CFG |= 0X05;
SPI0->DLY |=0X08;
SPI0->TXDATCTL |=0X07500000;

while (1)
{
//EXAMPLE_MasterStartTransfer();
while ((SPI0->STAT & SPI_STAT_TXRDY_MASK) == 0U)
{
}

SPI0->TXDAT = 0XAA;

}

This is our configuration in SPI. But there is no generation of clock and MOSI status changes. Kindly navigate us to configure properly.

[xiangjun_rong]

Hi,

Because the default value of SWM0->PINASSIGN_DATA[2] is 0xFFFF_FFFF, pls try to use the code

SYSCON->SYSAHBCLKCTRL0 |= (1<<7);

SWM0->PINASSIGN_DATA[2]=0x00;
SWM0->PINASSIGN_DATA[2] |= (0x1B)<<0;//port0-27
SWM0->PINASSIGN_DATA[2] |= (0x1A)<<8;//port0-26
SWM0->PINASSIGN_DATA[2] |= (0x1C)<<24;//PORT0-

Hope it can help you

BR

XiangJun Rong

[Sathiya_T]

As per your reference, clock generated properly but still no change in MOSI status

 SWM0->PINASSIGN_DATA[2] |= (0x1B)<<0;//port0-27
SWM0->PINASSIGN_DATA[2] |= (0x1A)<<8;//port0-26
SWM0->PINASSIGN_DATA[2] |= (0x18)<<24;//PORT0-24

SPI0->DIV =0X1D;
// SPI0->CFG = 0X15;
SPI0->DLY =0XF00;

SPI0->TXDATCTL =0X7410000;
SPI0->CFG |= 0X15;
while (1)
{
while ((SPI0->STAT & SPI_STAT_TXRDY_MASK) == 0U)
{
}
// SPI0->TXDATCTL |=0X075000FF;
SPI0->TXDAT = 0XAA;

}

[xiangjun_rong]

Hi,

Unfortunately, I have only LPCXPresso804(OM40001) board, where the 24 pins LPC804 is populated, the PIO0_24/26/27 are not routed to pads.

Pls try to move the MOSI to another pin and check if you can see the signal.

BR

XiangJun Rong

[Sathiya_T]

void SPI0_config(void)

{

//

//SYSCON->SYSAHBCLKCTRL0 |= 1<<11;  //Enable clock

//SYSCON->PRESETCTRL0 &=~(1<<11);             //SPI  clear

//SYSCON->PRESETCTRL0 |=(1<<11);

SYSCON->SYSAHBCLKCTRL0 |= 1<<7;             //SWM CLK

//SYSCON->PRESETCTRL0 &=~(1<<7);

//SYSCON->PRESETCTRL0 |=(1<<7);

SWM0->PINASSIGN_DATA[2]=0X00000000;

SWM0->PINASSIGN_DATA[2]|=(0X16)<<0;           //CLK PORT0-22

SWM0->PINASSIGN_DATA[2]|=(0X0F)<<8;          //MOSI PORT0-15

SWM0->PINASSIGN_DATA[2]|=(0X08)<<24;        //Chip select- SSEL0 PORT0-8

SYSCON->SYSAHBCLKCTRL0 |= 1<<11;  //Enable clock

SYSCON->SPI0CLKSEL|=1<<11;              //SPI CLK

SPI0->CFG = 0x125;                           //Master enable//CLK POLARITY 0X25;

SPI0->DLY =0x2000;                           //Enabled FRAME DELAY

SPI0->TXDATCTL =0X7430000;//843

SPI0->DIV = 0XA8;   

}

void send_byte(uint32_t txvalue)

{

while ((SPI0->STAT & SPI_STAT_TXRDY_MASK) == 0U)

    {

    }

SPI0->TXDAT = txvalue;

delay(20);

}

This is our updated configuration. Is the function is right? 

Here while passing the argument we not get the status MOSI pin but the clock generate properly. As a slave we connected ST7567 (FSTN display).

To transfer the data, we use send_byte() with required data as argument

[xiangjun_rong]

Hi,

I have tried your code, I suppose that the SPI clock is incorrect:

original line:

SYSCON->SPI0CLKSEL|=1<<11; //SPI CLK

change to

SYSCON->SPI0CLKSEL=1<<11; //SPI CLK

The SEL default value is 7, which means none of SPI clock. After you or with 1, it is still 7, you should have been set it as 0x01.

I used the following code, I can see clock signal SCK and MOSI from PIO0_15/PIO0_16 of LPCXPresso804 board.

Hope it can help you

BR

XiangJun Rong

#include <stdio.h>
#include "board.h"
#include "peripherals.h"
#include "pin_mux.h"
#include "clock_config.h"
#include "LPC804.h"
#include "fsl_debug_console.h"
void SPI0_config(void);
/* TODO: insert other include files here. */

/* TODO: insert other definitions and declarations here. */

/*
* @brief Application entry point.
*/
int main(void) {

/* Init board hardware. */
BOARD_InitBootPins();
BOARD_InitBootClocks();
BOARD_InitBootPeripherals();
#ifndef BOARD_INIT_DEBUG_CONSOLE_PERIPHERAL
/* Init FSL debug console. */
BOARD_InitDebugConsole();
#endif

PRINTF("Hello World\n");

/* Force the counter to be placed into memory. */
volatile static int i = 0 ;
/* Enter an infinite loop, just incrementing a counter. */
SPI0_config();
while (1)
{
while ((SPI0->STAT & SPI_STAT_TXRDY_MASK) == 0U)
{
}
// SPI0->TXDATCTL |=0X075000FF;
SPI0->TXDAT = 0XAA;
asm("nop");
}

while(1) {
i++ ;
/* 'Dummy' NOP to allow source level single stepping of
tight while() loop */
__asm volatile ("nop");
}
return 0 ;
}

void SPI0_config(void)
{
//
//SYSCON->SYSAHBCLKCTRL0 |= 1<<11; //Enable clock
//SYSCON->PRESETCTRL0 &=~(1<<11); //SPI clear
//SYSCON->PRESETCTRL0 |=(1<<11);

SYSCON->SYSAHBCLKCTRL0 |= 1<<7; //SWM CLK

//SYSCON->PRESETCTRL0 &=~(1<<7);
//SYSCON->PRESETCTRL0 |=(1<<7);

SWM0->PINASSIGN_DATA[2]=0X00000000;
SWM0->PINASSIGN_DATA[2]|=(0x10)<<0; //CLK PIO0_16PORT0-22
SWM0->PINASSIGN_DATA[2]|=(0X0F)<<8; //MOSI PORT0-15
SWM0->PINASSIGN_DATA[2]|=(0X08)<<24; //Chip select- SSEL0 PORT0-8

SYSCON->SYSAHBCLKCTRL0 |= 1<<11; //Enable clock

SYSCON->SPI0CLKSEL=1<<11; //SPI CLK
SPI0->CFG = 0x125; //Master enable//CLK POLARITY 0X25;
SPI0->DLY =0x2000; //Enabled FRAME DELAY
SPI0->TXDATCTL =0X7430000;//843

SPI0->DIV = 0XA8;
}