hal_spi.c

这是nrf24lu1的无线鼠标源代码,应用平台是keil c

/** @file
 * Implementation of the SPI HAL module
 * @author Ole Saether
 */
#include <Nordic\reg24lu1.h>
#include "hal_spi.h"

#define SPI_DATA    0x01
#define SPI_START   0x02
#define SPI_STOP    0x04

void hal_spi_master_init(hal_spi_clkdivider_t ck)
{
  uint8_t smctl;

  I3FR = 1;         // rising edge SPI ready detect
  P0EXP = 0x01;     // Map SPI master on P0
  INTEXP = 0x02;    // Select SPI master on IEX3
  SPIF = 0;         // Clear any pending interrupts
  switch(ck)
  {
    case SPI_CLK_DIV2:
      smctl = 0x11;
      break;

    case SPI_CLK_DIV4:
      smctl = 0x12;
      break;

    case SPI_CLK_DIV8:
      smctl = 0x13;
      break;

    case  SPI_CLK_DIV16:
      smctl = 0x14;
      break;

    case SPI_CLK_DIV32:
      smctl = 0x15;
      break;

    case SPI_CLK_DIV64:
    default:
      smctl = 0x16;
      break;
  }
  SMCTL = smctl;     // Enable SPI master with the specified divide factor
}

uint8_t hal_spi_master_read_write(uint8_t b)
{
  SPIF = 0;         // Clear interrupt request
  SMDAT = b;        // Start the SPI operation by writing the data
  while(SPIF == 0)  // Wait until SPI has finished transmitting
    ;
  return SMDAT;     // Return the the read byte
}