Software controlled SPI Master driver

Software controlled SPI Master driver. More...

Enumerations
enum	SPIFrequency_t {   Freq_125Kbps = 0,   Freq_250Kbps,   Freq_500Kbps,   Freq_1Mbps,   Freq_2Mbps,   Freq_4Mbps,   Freq_8Mbps }
enum	SPIModuleNumber {   SPI0 = 0,   SPI1 }
enum	SPIMode {   SPI_MODE0 = 0,   SPI_MODE1,   SPI_MODE2,   SPI_MODE3 }

Functions
uint32_t *	spi_master_init (SPIModuleNumber module_number, SPIMode mode, bool lsb_first)
	Function for initializing given SPI master with given configuration. More...
bool	spi_master_tx_rx (uint32_t *spi_base_address, uint16_t transfer_size, const uint8_t *tx_data, uint8_t *rx_data)
	Function for transferring/receiving data over SPI bus. More...

Detailed Description

Supported features:

• Operate two SPI masters independently or in parallel.
• Transmit and Receive given size of data through SPI.
• configure each SPI module separately through spi_master_init.

Enumeration Type Documentation

enum SPIFrequency_t

SPI master operating frequency

Enumerator
Freq_125Kbps	drive SClk with frequency 125Kbps
Freq_250Kbps	drive SClk with frequency 250Kbps
Freq_500Kbps	drive SClk with frequency 500Kbps
Freq_1Mbps	drive SClk with frequency 1Mbps
Freq_2Mbps	drive SClk with frequency 2Mbps
Freq_4Mbps	drive SClk with frequency 4Mbps
Freq_8Mbps	drive SClk with frequency 8Mbps

enum SPIModuleNumber

SPI master module number

Enumerator
SPI0	SPI module 0
SPI1	SPI module 1

enum SPIMode

SPI mode

Enumerator
SPI_MODE0	Sample data at rising edge of clock and shift serial data at falling edge
SPI_MODE1	sample data at falling edge of clock and shift serial data at rising edge
SPI_MODE2	sample data at falling edge of clock and shift serial data at rising edge
SPI_MODE3	Sample data at rising edge of clock and shift serial data at falling edge

Function Documentation

uint32_t* spi_master_init	(	SPIModuleNumber	module_number,
		SPIMode	mode,
		bool	lsb_first
	)

After initializing the given SPI master with given configuration, this function also test if the SPI slave is responding with the configurations by transmitting few test bytes. If the slave did not respond then error is returned and contents of the rx_data are invalid.

Parameters

module_number	SPI master number (SPIModuleNumber) to initialize.
mode	SPI master mode (mode 0, 1, 2 or 3 from SPIMode)
lsb_first	true if lsb is first bit to shift in/out as serial data on MISO/MOSI pins.

Returns

Return values

pointer	to direct physical address of the requested SPI module if init was successful
0,if	either init failed or slave did not respond to the test transfer

bool spi_master_tx_rx	(	uint32_t *	spi_base_address,
		uint16_t	transfer_size,
		const uint8_t *	tx_data,
		uint8_t *	rx_data
	)

If TWI master detects even one NACK from the slave or timeout occurs, STOP condition is issued and the function returns false.

Note

Make sure at least transfer_size number of bytes is allocated in tx_data/rx_data.

Parameters

spi_base_address	register base address of the selected SPI master module
transfer_size	number of bytes to transmit/receive over SPI master
tx_data	pointer to the data that needs to be transmitted
rx_data	pointer to the data that needs to be received

Returns

Return values

true	if transmit/reveive of transfer_size were completed.
false	if transmit/reveive of transfer_size were not complete and tx_data/rx_data points to invalid data.