xspips_slave_polled_example.c File Reference

Overview

This file contains a design example using the SPI controller in slave mode.

This examples performs transfers in polled mode and has been tested with Aardvark Analyzer as Master. This example echoes data which it receives from the master. The slave controller expects MAX_DATA bytes of data from the master to transmit onto the SPI bus which the slave will receive into its Rx buffer. It will poll until the Rx FIFO is filled with the Threshold limit of data which is set to MAX_DATA. On sending data, the master will receive dummy bytes in response. Master has to send MAX_DATA dummy bytes to read back the echoed data.

Note

The slave mode test needs an external master to send data to the Spi device. This example has been tested with Aardvark Analyzer as Master. The Clock Polarity and Phase should match between master and the slave.

 MODIFICATION HISTORY:

 Ver   Who Date     Changes



 2.0   sb  08/22/14  First release
       ms   04/05/17 Modified Comment lines in functions to
                     recognize it as documentation block for doxygen
                     generation.
 3.9   sb   07/05/23 Added support for system device-tree flow.

Functions
void	SpiSlaveRead (int ByteCount)
	This function reads from the Rx buffer. More...
void	SpiSlaveWrite (u8 *Sendbuffer, int ByteCount)
	This function writes Data into the Tx buffer. More...
int	SpiPsSlavePolledExample (u16 SpiDeviceId)
	The purpose of this function is to illustrate how to use the XSpiPs device driver in Slave mode. More...
int	main (void)
	Main function to call the SPI Slave Example. More...

Function Documentation

int main

(

void

)

Main function to call the SPI Slave Example.

Returns

• XST_SUCCESS if successful
• XST_FAILURE if not successful

Note

None

References SpiPsSlavePolledExample().

int SpiPsSlavePolledExample

(

u16

SpiDeviceId

)

The purpose of this function is to illustrate how to use the XSpiPs device driver in Slave mode.

This function reads data from a SPI Master and will echo it back to the Master.

Parameters

SpiDeviceId

is the Instance Id of SPI in the system.

Returns

• XST_SUCCESS if successful
• XST_FAILURE if not successful

Note

None

References XSpiPs_Config::BaseAddress, SpiSlaveRead(), SpiSlaveWrite(), XSpiPs_CfgInitialize(), XSPIPS_CR_CPHA_MASK, XSPIPS_CR_CPOL_MASK, XSpiPs_Disable, XSpiPs_Enable, XSpiPs_LookupConfig(), XSpiPs_SetOptions(), and XSpiPs_SetRXWatermark.

Referenced by main().

void SpiSlaveRead

(

int

ByteCount

)

This function reads from the Rx buffer.

Parameters

ByteCount

is the number of bytes to be read from Rx buffer.

Returns

None.

Note

None.

References XSpiPs_Config::BaseAddress, XSpiPs::Config, XSPIPS_IXR_RXNEMPTY_MASK, XSpiPs_ReadReg, and XSPIPS_SR_OFFSET.

Referenced by SpiPsSlavePolledExample().

void SpiSlaveWrite	(	u8 *	Sendbuffer,
		int	ByteCount
	)

This function writes Data into the Tx buffer.

Parameters

Sendbuffer	is the buffer whose data is to be sent onto the Tx FIFO.
ByteCount	is the number of bytes to be read from Rx buffer.

Returns

None.

Note

None.

References XSpiPs_Config::BaseAddress, XSpiPs::Config, XSPIPS_FIFO_DEPTH, XSPIPS_IXR_TXOW_MASK, XSpiPs_ReadReg, and XSPIPS_SR_OFFSET.

Referenced by SpiPsSlavePolledExample().