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siwicom/C/spi.c

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/*================================================================================================
spi.c SiWiCom copyright 2006 v1.0 (2006-05-11)
Name: Joakim Nilsson E-mail: mail@jopin.se
Name: Christoffer Martinsson E-mail: cm@cmtec.se
Description: Routines for SPI interface. Basic design by CM. Modifyed and extended by JN
for project SiWiCom 2006
SPI configuration is done by hardware.h witch must contain definitions for:
(X=letter i.e PORTX=PORTB, n=number i.e PXn=PB4)
SPI_PORT PORTX (Example: #define SPI_PORT PORTB) // PORTB as SPI-port
SPI_DDR DDRX (Example: #define SPI_DDR DDRB) // DDRB as direction for SPI pindirection
MOSI PXn (Example: #define MOSI PB3) // Master Out - Slave In
MISO PXn (Example: #define MISO PB4) // Master In - Slave Out
SCK PXn (Example: #define SCK PB5 // Serial Clock
Processor as SPI-master or SPI-slave, example:
#define _SPI_MASTER_
//#define _SPI_SLAVE_
If processor is defined as _SPI_MASTER_, Chip select port(s) (at least one, max 8) must be asigned as:
#define SPI_CS0_PORT PORTX
.
.
.
#define SPI_CS7_PORT PORTX
and SPI direction for the above asigned port(s) as:
#define SPI_CS0_DDR DDRX
.
.
.
#define SPI_CS7_DDR DDRX
and SPI pin(s) used for chip select as:
#define SPI_CS0 PXn
.
.
.
#define SPI_CS7 PXn
================================================================================================*/
#include "hardware.h"
#include <inttypes.h>
#include <avr/io.h>
#include "spi.h"
/*================================================================================================
Functions
================================================================================================*/
/*================================================================================================
spiWrite
Description: Write data to SPI.
Input: data to send
Return: -
------------------------------------------------------------------------------------------------*/
void spiWrite(uint8_t data)
{
SPDR = data;
while(!(SPSR & (1<<SPIF)));
}
/*================================================================================================
spiRead
Description: Read data from SPI buffer.
Input: -
Return: SPI-value
------------------------------------------------------------------------------------------------*/
uint8_t spiRead(void)
{
return SPDR;
}
/*================================================================================================
spiSetHighSpeed
Description: Set datatrasfer to fc/4.
Input: -
Return: -
------------------------------------------------------------------------------------------------*/
void spiSetHighSpeed(void)
{
SPCR &= ~(1<<SPR0);
SPCR &= ~(1<<SPR1);
}
/*================================================================================================
spiSetLowSpeed
Description: Set datatrasfer to fc/64.
Input: -
Return: -
------------------------------------------------------------------------------------------------*/
void spiSetLowSpeed(void)
{
SPCR &= ~(1<<SPR0);
SPCR |= (1<<SPR1);
}
/*================================================================================================
spiInit
Description: Init SPI interface as master or slave depending on the "hardware.h" configuration.
Input: -
Return: -
------------------------------------------------------------------------------------------------*/
void spiInit(void)
{
#ifdef _SPI_MASTER_ //If defined as master in hardware.h
#ifdef SPI_CS0
SPI_CS0_DDR |= (1<<SPI_CS0);
SPI_CS0_PORT |= (1<<SPI_CS0);
#endif
#ifdef SPI_CS1
SPI_CS1_DDR |=(1<<SPI_CS1);
SPI_CS1_PORT |= (1<<SPI_CS1);
#endif
#ifdef SPI_CS2
SPI_CS2_DDR |=(1<<SPI_CS2);
SPI_CS2_PORT |= (1<<SPI_CS2);
#endif
#ifdef SPI_CS3
SPI_CS3_DDR |=(1<<SPI_CS3);
SPI_CS3_PORT |= (1<<SPI_CS3);
#endif
#ifdef SPI_CS4
SPI_CS4_DDR |=(1<<SPI_CS4);
SPI_CS4_PORT |= (1<<SPI_CS4);
#endif
#ifdef SPI_CS5
SPI_CS5_DDR |=(1<<SPI_CS5);
SPI_CS5_PORT |= (1<<SPI_CS5);
#endif
#ifdef SPI_CS6
SPI_CS6_DDR |=(1<<SPI_CS6);
SPI_CS6_PORT |= (1<<SPI_CS6);
#endif
#ifdef SPI_CS7
SPI_CS7_DDR |=(1<<SPI_CS7);
SPI_CS7_PORT |= (1<<SPI_CS7);
#endif
SPI_DDR |= (1<<MOSI)|(1<<SCK); // MOSI and SCLK as output
SPI_PORT |= (1<<MISO) ; // Pullup on SO (slave out)
SPCR |= (1<<SPE)|(1<<MSTR)|(1<<SPI2X); // SPI enable, SPI-Master, SC = fc/2
#elif _SPI_SLAVE_ //If defined as slave in hardware.h
SPI_DDR |= (1<<MISO); // MOSI and SCLK as output
SPI_PORT |=(1<<SS); // Pull-Up on SS
SPCR |= (1<<SPE); // SPI enable, SPI-Slave
#endif
}
/*================================================================================================
spiChipSelect
Description: Select device for communication via SPI. Protects chipselect on two devices at the
same time and secure that chosen chipselect is an initialised legal channel.
Input: uint8_t (The number of the desired chipselect. (Between 0 and 7) )
Return: -
------------------------------------------------------------------------------------------------*/
void spiChipSelect(uint8_t chipselect){
/*All chipselectports disabled (high state)*/
#ifdef SPI_CS0
SPI_CS0_PORT |=(1<<SPI_CS0);
#endif
#ifdef SPI_CS1
SPI_CS1_PORT |=(1<<SPI_CS1);
#endif
#ifdef SPI_CS2
SPI_CS2_PORT |=(1<<SPI_CS2);
#endif
#ifdef SPI_CS3
SPI_CS3_PORT |=(1<<SPI_CS3);
#endif
#ifdef SPI_CS4
SPI_CS4_PORT |=(1<<SPI_CS4);
#endif
#ifdef SPI_CS5
SPI_CS5_PORT |=(1<<SPI_CS5);
#endif
#ifdef SPI_CS6
SPI_CS6_PORT |=(1<<SPI_CS6);
#endif
#ifdef SPI_CS7
SPI_CS7_PORT |=(1<<SPI_CS7);
#endif
/*Selected port as chipselect*/
#ifdef SPI_CS0
if(chipselect==0)
SPI_CS0_PORT &=~(1<<SPI_CS0);
#endif
#ifdef SPI_CS1
if(chipselect==1)
SPI_CS1_PORT &=~(1<<SPI_CS1);
#endif
#ifdef SPI_CS2
if(chipselect==2)
SPI_CS2_PORT &=~(1<<SPI_CS2);
#endif
#ifdef SPI_CS3
if(chipselect==3)
SPI_CS3_PORT &=~(1<<SPI_CS3);
#endif
#ifdef SPI_CS4
if(chipselect==4)
SPI_CS4_PORT &=~(1<<SPI_CS4);
#endif
#ifdef SPI_CS5
if(chipselect==5)
SPI_CS5_PORT &=~(1<<SPI_CS5);
#endif
#ifdef SPI_CS6
if(chipselect==6)
SPI_CS6_PORT &=~(1<<SPI_CS6);
#endif
#ifdef SPI_CS7
if(chipselect==7)
SPI_CS7_PORT &=~(1<<SPI_CS7);
#endif
}
/*================================================================================================
spiChipDeSelect
Description: Deselect all SPI channels
Input: -
Return: -
------------------------------------------------------------------------------------------------*/
void spiChipDeSelect(void)
{
/*All chipselectports disabled (high state)*/
#ifdef SPI_CS0
SPI_CS0_PORT |=(1<<SPI_CS0);
#endif
#ifdef SPI_CS1
SPI_CS1_PORT |=(1<<SPI_CS1);
#endif
#ifdef SPI_CS2
SPI_CS2_PORT |=(1<<SPI_CS2);
#endif
#ifdef SPI_CS3
SPI_CS3_PORT |=(1<<SPI_CS3);
#endif
#ifdef SPI_CS4
SPI_CS4_PORT |=(1<<SPI_CS4);
#endif
#ifdef SPI_CS5
SPI_CS5_PORT |=(1<<SPI_CS5);
#endif
#ifdef SPI_CS6
SPI_CS6_PORT |=(1<<SPI_CS6);
#endif
#ifdef SPI_CS7
SPI_CS7_PORT |=(1<<SPI_CS7);
#endif
}
/*================================================================================================
End
================================================================================================*/
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