spi.c

MSP430单片机的阅读器源码

/*spi.c*/
#include "msp430x22x4.h"
#include "hardware.h"
#include "cc2500.h"
#include "spi.h"

void TI_CC_Wait(unsigned int cycles)
{
  while(cycles>15)                          // 15 cycles consumed by overhead
    cycles = cycles - 6;                    // 6 cycles consumed each iteration
}

void TI_CC_SPISetup(void)
{
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;
  TI_CC_CSn_PxDIR |= TI_CC_CSn_PIN;         // /CS disable

  // Config bitbang pins
  TI_CC_SPI_BITBANG_PxOUT |= TI_CC_SPI_BITBANG_SIMO|TI_CC_SPI_BITBANG_UCLK;
  TI_CC_SPI_BITBANG_PxDIR |= TI_CC_SPI_BITBANG_SIMO | TI_CC_SPI_BITBANG_UCLK;
}

// Output eight-bit value using selected bit-bang pins
void TI_CC_SPI_bitbang_out(unsigned char value)
{
  unsigned char x;

  for(x=8;x>0;x--)
  {
    if(value & 0x80)                                     // If bit is high...
      TI_CC_SPI_BITBANG_PxOUT |= TI_CC_SPI_BITBANG_SIMO; // Set SIMO high...
    else
      TI_CC_SPI_BITBANG_PxOUT &= ~TI_CC_SPI_BITBANG_SIMO;// Set SIMO low...
    value = value << 1;                                  // Rotate bits

    TI_CC_SPI_BITBANG_PxOUT &= ~TI_CC_SPI_BITBANG_UCLK;  // Set clock low
    TI_CC_SPI_BITBANG_PxOUT |= TI_CC_SPI_BITBANG_UCLK;   // Set clock high
  }
}

// Input eight-bit value using selected bit-bang pins
unsigned char TI_CC_SPI_bitbang_in()
{
  unsigned char x=0,shift=0;
  int y;

  // Determine how many bit positions SOMI is from least-significant bit
  x = TI_CC_SPI_BITBANG_SOMI;
  while(x>1)
  {
    shift++;
    x = x >> 1;
  };

  x = 0;
  for(y=8;y>0;y--)
  {
    TI_CC_SPI_BITBANG_PxOUT &= ~TI_CC_SPI_BITBANG_UCLK;// Set clock low
    TI_CC_SPI_BITBANG_PxOUT |= TI_CC_SPI_BITBANG_UCLK;// Set clock high

    x = x << 1;                             // Make room for next bit
    x = x | ((TI_CC_SPI_BITBANG_PxIN & TI_CC_SPI_BITBANG_SOMI) >> shift);
  }                                         // Store next bit
  return(x);
}

void TI_CC_SPIWriteReg(unsigned char addr, unsigned char value)
{
    TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;      // /CS enable
    while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI); // Wait CCxxxx ready
    TI_CC_SPI_bitbang_out(addr);            // Send address
    TI_CC_SPI_bitbang_out(value);           // Send data
    TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;       // /CS disable
}

void TI_CC_SPIWriteBurstReg(unsigned char addr, unsigned char *buffer, unsigned char count)
{
    unsigned char i;

    TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;      // /CS enable
    while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI); // Wait CCxxxx ready
    TI_CC_SPI_bitbang_out(addr | TI_CCxxx0_WRITE_BURST);   // Send address
    for (i = 0; i < count; i++)
      TI_CC_SPI_bitbang_out(buffer[i]);     // Send data
    TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;       // /CS disable
}

unsigned char TI_CC_SPIReadReg(unsigned char addr)
{
  unsigned char x;

  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;        // /CS enable
  TI_CC_SPI_bitbang_out(addr | TI_CCxxx0_READ_SINGLE);//Send address
  x = TI_CC_SPI_bitbang_in();               // Read data
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;         // /CS disable

  return x;
}

void TI_CC_SPIReadBurstReg(unsigned char addr, unsigned char *buffer, unsigned char count)
{
  unsigned char i;

  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;        // /CS enable
  while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI); // Wait CCxxxx ready
  TI_CC_SPI_bitbang_out(addr | TI_CCxxx0_READ_BURST);    // Send address
  for (i = 0; i < count; i++)
    buffer[i] = TI_CC_SPI_bitbang_in();     // Read data
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;         // /CS disable
}

unsigned char TI_CC_SPIReadStatus(unsigned char addr)
{
  unsigned char x;

  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;        // /CS enable
  while (TI_CC_SPI_BITBANG_PxIN & TI_CC_SPI_BITBANG_SOMI); // Wait CCxxxx ready
  TI_CC_SPI_bitbang_out(addr | TI_CCxxx0_READ_BURST);      // Send address
  x = TI_CC_SPI_bitbang_in();               // Read data
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;         // /CS disable

  return x;
}

void TI_CC_SPIStrobe(unsigned char strobe)
{
  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;        // /CS enable
  while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI);// Wait for CCxxxx ready
  TI_CC_SPI_bitbang_out(strobe);            // Send strobe
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;         // /CS disable
}

void TI_CC_PowerupResetCCxxxx(void)
{
  // Sec. 27.1 of CC2500 datasheet
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;
  TI_CC_Wait(30);
  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;
  TI_CC_Wait(30);
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;
  TI_CC_Wait(45);

  TI_CC_CSn_PxOUT &= ~TI_CC_CSn_PIN;
  while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI);
  TI_CC_SPI_bitbang_out(TI_CCxxx0_SRES);
  while (TI_CC_SPI_BITBANG_PxIN&TI_CC_SPI_BITBANG_SOMI);
  TI_CC_CSn_PxOUT |= TI_CC_CSn_PIN;
}