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/*
* ssp.cpp
*
* Created on: 2011/07/30
* Author: lynxeyed
*/
#include "gpio.h"
#include "SPI.h"
SSP SPI;
SSP::SSP() //define constructor
{
this->port = marySSP0;
bitOrder = LSBFIRST;
divider = SPI_CLOCK_DIV4; //Arduino's default
dataMode = SPI_MODE0;
bitlength = 8;
setClockDivider(divider);
setBitLength(bitlength);
setBitOrder(LSBFIRST);
begin();
}
SSP::~SSP() // destructor
{
}
void SSP::begin()
{
ssp_begin(port,divider,dataMode,bitlength);
return;
}
void SSP::begin(SSP_PORT port)
{
this->port = port;
ssp_begin(port,divider,dataMode,bitlength);
return;
}
void SSP::setBitLength(int bitlength)
{
this->bitlength = bitlength;
return;
}
void SSP::end()
{
LPC_SSP0->CR1 &= ~(1U << 1); //the SPI controller is disabled
return;
}
void SSP::setBitOrder(SSP_BIT_ORDER bitOrder)
{
this->bitOrder = bitOrder;
if(bitOrder == MSBFIRST)
{
;
}
else
{
;
}
return;
}
void SSP::setClockDivider(SSP_CLK_DIVIDER divider) //See also SSP1CLKDIV(user.manual p.24)
{
this->divider = divider;
return;
}
void SSP::setDataMode(SSP_DATA_MODE mode)
{
this->dataMode = mode;
}
unsigned long SSP::transfer(unsigned long txdata)
{
return ssp_transfer(txdata);
}
// lowlevel
void ssp_begin(SSP_PORT port,SSP_CLK_DIVIDER divider,SSP_DATA_MODE dataMode,int bitlength)
{
// Initialize SSP
// PIO0_2(CN3_3) : SSEL
// PIO0_6(CN4_3) : SCLK
// PIO0_8(CN4_5) : MISO
// PIO0_9(CN4_7) : MOSI
volatile int sspPhase; //SSP's clock phase
pinMode(P0_2,OUTPUT); // PIO0_2(CN3_3) out
LPC_IOCON->PIO0_2 = 0x00000000; // GPIO, disable pu/pd mos
digitalWrite(P0_2,HIGH); // PIO0_2(CN3_3) = 1
switch(port){
case LPCXSSP0:
LPC_IOCON->SCK_LOC = 0x00000001;//2; // SCK is PIO2_11
LPC_IOCON->PIO2_11 = 0x00000001;//2; // SCK, disable pu/pd mos
break;
case marySSP0:
LPC_IOCON->SCK_LOC = 0x00000002; // SCK is PIO0_6
LPC_IOCON->PIO0_6 = 0x00000002; // SCK, disable pu/pd mos
break;
default: //default = MARY
LPC_IOCON->SCK_LOC = 0x00000002; // SCK is PIO0_6
LPC_IOCON->PIO0_6 = 0x00000002; // SCK, disable pu/pd mos
break;
}
LPC_IOCON->PIO0_9 = 0x00000001; // MOSI, disable pu/pd mos
LPC_IOCON->PIO0_8 = 0x00000011; // MISO, enable pu/pd mos
//
// Initialize SPI
//
LPC_SYSCON->PRESETCTRL |= (0x1<<0);
LPC_SYSCON->SYSAHBCLKCTRL |= (1<<11);
//clockDivider
LPC_SYSCON->SSP0CLKDIV = 0x01; // Divided by 1
switch(divider)
{
case SPI_CLOCK_DIV1: //Special code
LPC_SYSCON->SSP0CLKDIV = 0x01;
break;
case SPI_CLOCK_DIV2:
LPC_SYSCON->SSP0CLKDIV = 0x02;
break;
case SPI_CLOCK_DIV4:
LPC_SYSCON->SSP0CLKDIV = 0x04;
break;
case SPI_CLOCK_DIV8:
LPC_SYSCON->SSP0CLKDIV = 0x08;
break;
case SPI_CLOCK_DIV16:
LPC_SYSCON->SSP0CLKDIV = 0x10;
break;
case SPI_CLOCK_DIV32:
LPC_SYSCON->SSP0CLKDIV = 0x20;
break;
case SPI_CLOCK_DIV64:
LPC_SYSCON->SSP0CLKDIV = 0x40;
break;
case SPI_CLOCK_DIV128:
LPC_SYSCON->SSP0CLKDIV = 0x80;
break;
default:
LPC_SYSCON->SSP0CLKDIV = 0x04; //default
break;
}
// dataMode(MODE0,1,2,3)
switch(dataMode)
{
// SSP0CR0::bit6 = CPOL, bit7 = CPHA
case SPI_MODE0: // CPOL=0, CPHA = 0
sspPhase = 0;
break;
case SPI_MODE1: // CPOL=0, CPHA = 1
sspPhase = 1;
break;
case SPI_MODE2: // CPOL=1, CPHA = 0
sspPhase = 2;
break;
case SPI_MODE3: // CPOL=1, CPHA = 1
sspPhase = 3;
break;
case TI_SERIAL_MODE:
default:
break;
}//end switch(dataMode)
// bitLength
LPC_SSP0->CR0 = (sspPhase << 6);
LPC_SSP0->CR0 |= (bitlength - 1);
//SCLKDivider
LPC_SSP0->CPSR = 2; //2 or more but even value
// Enable the SSP Interrupt
NVIC_EnableIRQ(SSP0_IRQn);
NVIC_SetPriority(SSP0_IRQn, 3);
// Device select as master, SSP Enabled (see also user.manual p.143)
LPC_SSP0->CR1 = (1U << 1);
return;
}
unsigned long ssp_transfer(unsigned long txdata)
{
volatile unsigned long rxdata;
// Tx
while ((LPC_SSP0->SR & ((1U<<1)|(1U<<4))) != 1U << 1);
// Send a byte
LPC_SSP0->DR = txdata;
// Wait until the Busy bit is cleared
while ( LPC_SSP0->SR & (1<<4) );
// Rx
while ((LPC_SSP0->SR & (1U<<2)) != 1U << 2 );
rxdata = LPC_SSP0->DR;
return rxdata;
}
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