spi.c File Reference

SPI Driver AVR8. More...

#include "user_config.h"
#include <stdlib.h>
#include "spi.h"

Go to the source code of this file.

Functions
void	SPI0_Speed (uint32_t speed)
	Set AVR SPI bus rate in HZ. More...
uint32_t	SPI0_Get_Speed (void)
	Return previously saved SPI BUS rate in HZ. More...
void	SPI0_Mode (int mode)
	Set SPI clock mode. More...
int	SPI0_Get_Mode (void)
	Return saved SPI mode as set by SPI0_Mode(). More...
void	SPI0_Init (uint32_t speed)
	Initialize SPI0 device. See Atmel App Note AVR151 Set default speed, IO pins and mode. More...
uint8_t	SPI0_TXRX_Byte (uint8_t Data)
	SPI read/Write byte. More...
void	SPI0_TX (uint8_t *data, int count)
	SPI buffered write functions. More...
void	SPI0_TXRX (uint8_t *data, int count)
	HSPI write and read using FIFO. More...
void	SPI0_RX (uint8_t *data, int count)
	HSPI read using FIFO. More...

Variables
static uint32_t	SPI0_Speed_value = 0
	Saved SPI bus speed. More...
static int	SPI0_Mode_value = 0
	Saved SPI Mode. More...
static int	SPI0_Init_state = 0
	SPI0 initialization flag. More...

Detailed Description

SPI Driver AVR8.

Edit History

• [1.0] [Mike Gore] Initial revision of file.

Copyright

Copyright © 2014-2020 Mike Gore, Inc. All rights reserved.

GNU Public License.

Author

Mike Gore

Definition in file spi.c.

Function Documentation

SPI0_Get_Mode()

int SPI0_Get_Mode

(

void

)

Return saved SPI mode as set by SPI0_Mode().

Returns

saved mode.

Definition at line 180 of file spi.c.

SPI0_Get_Speed()

uint32_t SPI0_Get_Speed

(

void

)

Return previously saved SPI BUS rate in HZ.

Returns

SPI clock rate in HZ.

Definition at line 128 of file spi.c.

SPI0_Init()

void SPI0_Init

(

uint32_t

speed

)

Initialize SPI0 device. See Atmel App Note AVR151 Set default speed, IO pins and mode.

Set SPI clock mode 0 SPI Mode CPOL CPHA Sample 0 0 0 Leading (Rising) Edge

Definition at line 192 of file spi.c.

Referenced by spi_init().

SPI0_Mode()

void SPI0_Mode

(

int

mode

)

Set SPI clock mode.

Parameters

[in]

mode

valid mades: * SPI Mode CPOL CPHA Sample * 0 0 0 Leading (Rising) Edge * 1 0 1 Trailing (Falling) Edge * 2 1 0 Leading (Falling) Edge * 3 1 1 Trailing (Rising) Edge *

Returns

void

Definition at line 150 of file spi.c.

Referenced by SPI0_Init(), and spi_init().

SPI0_RX()

void SPI0_RX	(	uint8_t *	data,
		int	count
	)

HSPI read using FIFO.

Parameters

[in]	*data	receive buffer
[in]	count	number of bytes to read

Returns

void

Definition at line 297 of file spi.c.

Referenced by spi_RX(), and spi_RX_buffer().

SPI0_Speed()

void SPI0_Speed

(

uint32_t

speed

)

Set AVR SPI bus rate in HZ.

• Compute precsale rate from desired frequency in HZ.
  • Slowest rate: F_CPU/128.
  • Fastest rate: F_CPU/2.
• Precsale value is truncated not rounded.
• Valid precsle values are 2,4,8,16,32,64,128.

  /// SPI2X   SPR1    SPR0     SCK Frequency
  /// 1       0       0        fosc/2
  /// 0       0       0        fosc/4
  /// 1       0       1        fosc/8
  /// 0       0       1        fosc/16
  /// 1       1       0        fosc/32
  /// 0       1       0        fosc/64
  /// 1       1       1        fosc/64
  /// 0       1       1        fosc/128
  /// 

  @param[in] speed: SPI clock rate in HZ.
  
  @return  void 
  

Save speed value

Definition at line 46 of file spi.c.

Referenced by SPI0_Init().

SPI0_TX()

void SPI0_TX	(	uint8_t *	data,
		int	count
	)

SPI buffered write functions.

HSPI write using FIFO

Parameters

[in]	*data	transmit buffer
[in]	count	number of bytes to write

Returns

void

Definition at line 264 of file spi.c.

Referenced by spi_TX(), and spi_TX_buffer().

SPI0_TXRX()

void SPI0_TXRX	(	uint8_t *	data,
		int	count
	)

HSPI write and read using FIFO.

Parameters

[in]	*data	transmit / receive buffer
[in]	count	number of bytes to write / read

Returns

void

Definition at line 281 of file spi.c.

Referenced by spi_TXRX(), and spi_TXRX_buffer().

SPI0_TXRX_Byte()

uint8_t SPI0_TXRX_Byte

(

uint8_t

Data

)

SPI read/Write byte.

• We Write and read at the same time.
• If we want to read only set Data to 0xff.

Parameters

[in]

Data

Data to send.

Returns

Data received.

Definition at line 245 of file spi.c.

Referenced by ppr_set(), SPI0_Init(), SPI0_RX(), SPI0_TX(), and SPI0_TXRX().

Variable Documentation

SPI0_Init_state

int SPI0_Init_state = 0

static

SPI0 initialization flag.

Definition at line 187 of file spi.c.

Referenced by SPI0_Init().

SPI0_Mode_value

int SPI0_Mode_value = 0

static

Saved SPI Mode.

See also

SPI0_Mode().

Definition at line 136 of file spi.c.

Referenced by SPI0_Get_Mode(), and SPI0_Mode().

SPI0_Speed_value

uint32_t SPI0_Speed_value = 0

static

Saved SPI bus speed.

Definition at line 22 of file spi.c.

Referenced by SPI0_Get_Speed(), and SPI0_Speed().