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#include <avr/io.h>
#include "ssc.h"
//-------------------------------------- Hardware specific definitions --------------------------------------
#define PORTR_SPI PINB
#define PORTW_SPI PORTB //Port to which the sd-card is connected (SPI Port)
#define PORT_MISO PORTB6 //Port Pin that is connected to the DO of the MMC/SD-card
#define PORT_MOSI PORTB5 //Port Pin that is connected to DI of the MMC/SD-card
#define PORT_SCK PORTB7 //Port Pin that is connected the CLK of the MMC/SD-card
#define PORT_SS PORTB4 //Slave Select is not used in SPI Master Mode, but must be defined
#define PORT_CS PORTB4 //Port Pin that is connected to /CS of the MMC/SD-Karte
#ifdef USE_SDLOGGER
#define __SD_INTERFACE_INVERTED // the interface between the controller and the SD-card uses an inverting leveltranslator (transistorinverter)
#endif // and therefore the signals to or from the memorycard have to be inverted.
#ifdef USE_FOLLOWME // uses resitors, therefore its not inverted
//#define __SD_INTERFACE_INVERTED // the interface between the controller and the MMC/SD-card uses an inverting leveltranslator (transistorinverter)
#endif
#define DDR_SPI DDRB
#define DD_MISO DDB6 //Port Pin that is connected to the DO of the MMC/SD-card
#define DD_MOSI DDB5 //Port Pin that is connected to DI of the MMC/SD-card
#define DD_SCK DDB7 //Port Pin that is connected the CLK of the MMC/SD-card
#define DD_SS DDB4 //Slave Select is not used in SPI Master Mode, but must be defined
#define DD_CS DDB4 //Port Pin that is connected to /CS of the MMC/SD-Karte
// for compatibility reasons gcc3.x <-> gcc4.x
#ifndef SPCR
#define SPCR SPCR0
#endif
#ifndef SPIE
#define SPIE SPIE0
#endif
#ifndef SPE
#define SPE SPE0
#endif
#ifndef DORD
#define DORD DORD0
#endif
#ifndef MSTR
#define MSTR MSTR0
#endif
#ifndef CPOL
#define CPOL CPOL0
#endif
#ifndef CPHA
#define CPHA CPHA0
#endif
#ifndef SPR1
#define SPR1 SPR01
#endif
#ifndef SPR0
#define SPR0 SPR00
#endif
#ifndef SPDR
#define SPDR SPDR0
#endif
#ifndef SPSR
#define SPSR SPSR0
#endif
#ifndef SPIF
#define SPIF SPIF0
#endif
#ifndef WCOL
#define WCOL WCOL0
#endif
#ifndef SPI2X
#define SPI2X SPI2X0
#endif
//________________________________________________________________________________________________________________________________________
// Function: SSC_Init(void);
//
// Description: This function initialises the synchronus serial channel to the sdcard.
//
//
// Returnvalue: none
//________________________________________________________________________________________________________________________________________
void SSC_Init(void)
{
// Set MOSI,SCK and CS as output
DDR_SPI |= (1<<DD_MOSI)|(1<<DD_SCK)|(1<<DD_CS);
// set MISO as input
DDR_SPI &= ~(1<<DD_MISO);
SSC_Disable();
// 20MHz / 32 = 625 kHz
#ifdef __SD_INTERFACE_INVERTED
SPCR = (1<<SPE)|(1<<MSTR)|(0<<DORD)|(1<<CPOL)|(0<<CPHA)|(1<<SPR1)|(0<<SPR0); // Enable SSC in mastermode, inverted clockpolarity (idle high)
#else
SPCR = (1<<SPE)|(1<<MSTR)|(0<<DORD)|(0<<CPOL)|(0<<CPHA)|(1<<SPR1)|(0<<SPR0); // Enable SSC in mastermode, noninverted clockpolarity (idle low)
#endif
SPSR |= (1<<SPI2X);
// set port pin as input pullup for SD-Card switch
#ifdef USE_FOLLOWME
PORTB |= (1 << PORTB2);
DDRB &= ~(1 << DDB2);
#endif
#ifdef USE_SDLOGGER
PORTB |= (1 << PORTB3);
DDRB &= ~(1 << DDB3);
#endif
}
void SSC_Deinit(void)
{
SSC_Disable();
SPCR = 0;
SPSR = 0;
}
//________________________________________________________________________________________________________________________________________
// Function: SSC_GetChar(void);
//
// Description: This function reads one byte from the SSC
//
//
// Returnvalue: the byte received.
//________________________________________________________________________________________________________________________________________
uint8_t SSC_GetChar (void)
{
uint8_t Byte = 0;
#ifdef __SD_INTERFACE_INVERTED
SPDR = 0x00; // send dummy byte to initiate the reading
#else
SPDR = 0xFF; // send dummy byte to initiate the reading
#endif
while(!(SPSR & (1<<SPIF)))
{
// wait until the data has been read.
}
Byte = SPDR;
#ifdef __SD_INTERFACE_INVERTED
Byte = ~Byte;
#endif
return(Byte);
}
//________________________________________________________________________________________________________________________________________
// Function: SSC_PutChar(u8 Byte);
//
// Description: This function writes one byte to the SSC
//
//
// Returnvalue: none
//________________________________________________________________________________________________________________________________________
void SSC_PutChar (uint8_t Byte)
{
#ifdef __SD_INTERFACE_INVERTED
SPDR = ~Byte; // send one byte of data to the SSC
#else
SPDR = Byte; // send one byte of data to the SSC
#endif
while(!(SPSR & (1<<SPIF)))
{
// wait until the data has been sent.
}
}
//________________________________________________________________________________________________________________________________________
// Function: SSC_Disable(void);
//
// Description: This function enables chipselect of the sdcard (active low)
//
//
// Returnvalue: none
//________________________________________________________________________________________________________________________________________
void SSC_Disable(void)
{
#ifdef __SD_INTERFACE_INVERTED
PORTW_SPI &= ~(1<<PORT_CS); // disable chipselect of the sdcard (active low).
#else
PORTW_SPI |= (1<<PORT_CS); // disable chipselect of the sdcard (active low).
#endif
}
//________________________________________________________________________________________________________________________________________
// Function: SSC_Enable(void);
//
// Description: This function disables chipselect of the sdcard (active low)
//
//
// Returnvalue: none
//________________________________________________________________________________________________________________________________________
void SSC_Enable(void)
{
#ifdef __SD_INTERFACE_INVERTED
PORTW_SPI |= (1<<PORT_CS); // enable chipselect of the sdcard (active low).
#else
PORTW_SPI &= ~(1<<PORT_CS); // enable chipselect of the sdcard (active low).
#endif
}