[LPC1756 EVM] SPI 테스트

[LPC1756 EVM] SPI 테스트

LPC1756 SPI 초기화 함수

void SPI0_Init(void)
{
    int i;
    volatile unsigned char Dummy;
    
    //SPI Power On
    PCONP |= (1 << 21);    

   //SPI 핀설정    
    PINSEL0 |= 0x80000000;
    PINSEL1 |= 0x28;    

    PCLKSEL1 |= 0x400;   //CCLK
//    PCLKSEL1 |= 0x800;    //    CCLK/2
//    PCLKSEL1 |= 0xC00;    //    CCLK/8

   SPI0_SetSpeed(SPI_SPEED_1MHZ);
  
  //SSP disable
  SSP0CR1_bit.SSE = 0;
   
  /* Set DSS data to 8-bit, Frame format SPI, CPOL = 0, CPHA = 0, and SCR is 15 */
  SSP0CR0 = 0x0007;

  /* SSPCPSR clock prescale register, master mode, minimum divisor is 0x02 */
  SSP0CPSR = 0x2;

  for ( i = 0; i < FIFOSIZE; i++ )
  {
    Dummy = SSP0DR;   /* clear the RxFIFO */
  }

  //NVIC_IntEnable(NVIC_SSP1);
  //NVIC_IntPri(NVIC_SSP1,HIGHEST_PRIORITY);

  // SSP Enabled
  SSP0CR1 = SSPCR1_SSE;
}

SPI 클럭 설정 PCLKSEL1에서 아래와 같이 설정 가능하다.
00 PCLK_peripheral = CCLK/4 00
01 PCLK_peripheral = CCLK
10 PCLK_peripheral = CCLK/2
11 PCLK_peripheral = CCLK/8, except for CAN1, CAN2, and
CAN filtering when “11” selects = CCLK/6.


LPC1756 SPI 송수신 함수

SUINT SPI0_WriteReadByte(SUINT Data)
{
    //TxFIFO is not full
    while ( !(SSP0SR & SSPSR_TNF) );
    SSP0DR = Data;

    //Wait until the Busy bit is cleared 
    while ( !(SSP0SR & SSPSR_RNE) );
    return SSP0DR;  
}

SPI 모드 설정 레지스터