xspips.h File Reference

#include "xstatus.h"
#include "xspips_hw.h"

Classes
struct	XSpiPs_Config
struct	XSpiPs
Defines
#define	XSPIPS_H
#define	XSpiPs_IsManualStart(InstancePtr)
#define	XSpiPs_IsManualChipSelect(InstancePtr)
#define	XSpiPs_IsDecodeSSelect(InstancePtr)
#define	XSpiPs_IsMaster(InstancePtr)
#define	XSpiPs_SetSlaveIdle(InstancePtr, RegisterValue)
#define	XSpiPs_GetSlaveIdle(InstancePtr)
#define	XSpiPs_SetTXWatermark(InstancePtr, RegisterValue)
#define	XSpiPs_GetTXWatermark(InstancePtr) XSpiPs_In32((InstancePtr->Config.BaseAddress) + XSPIPS_TXWR_OFFSET)
#define	XSpiPs_SetRXWatermark(InstancePtr, RegisterValue)
#define	XSpiPs_GetRXWatermark(InstancePtr) XSpiPs_In32((InstancePtr->Config.BaseAddress) + XSPIPS_RXWR_OFFSET)
#define	XSpiPs_Enable(InstancePtr)
#define	XSpiPs_Disable(InstancePtr) XSpiPs_Out32((InstancePtr->Config.BaseAddress) + XSPIPS_ER_OFFSET, 0)
Configuration options
The following options are supported to enable/disable certain features of an SPI device. Each of the options is a bit mask, so more than one may be specified. The Master option configures the SPI device as a master. By default, the device is a slave. The Active Low Clock option configures the device's clock polarity. Setting this option means the clock is active low and the SCK signal idles high. By default, the clock is active high and SCK idles low. The Clock Phase option configures the SPI device for one of two transfer formats. A clock phase of 0, the default, means data is valid on the first SCK edge (rising or falling) after the slave select (SS) signal has been asserted. A clock phase of 1 means data is valid on the second SCK edge (rising or falling) after SS has been asserted. The Slave Select Decode Enable option selects how the SPI_SS_outN are controlled by the SPI Slave Select Decode bits. 0: Use this setting for the standard configuration of up to three slave select outputs. Only one of the three slave select outputs will be low. (Default) 1: Use this setting for the optional configuration of an additional decoder to support 8 slave select outputs. SPI_SS_outN reflects the value in the register. The SPI Force Slave Select option is used to enable manual control of the signals SPI_SS_outN. 0: The SPI_SS_outN signals are controlled by the SPI controller during transfers. (Default) 1: The SPI_SS_outN signal indicated by the Slave Select Control bit is forced active (driven low) regardless of any transfers in progress. NOTE: The driver will handle setting and clearing the Slave Select when the user sets the "FORCE_SSELECT_OPTION". Using this option will allow the SPI clock to be set to a faster speed. If the SPI clock is too fast, the processor cannot empty and refill the FIFOs before the TX FIFO is empty When the SPI hardware is controlling the Slave Select signals, this will cause slave to be de-selected and terminate the transfer. The Manual Start option is used to enable manual control of the Start command to perform data transfer. 0: The Start command is controlled by the SPI controller during transfers(Default). Data transmission starts as soon as there is data in the TXFIFO and stalls when the TXFIFO is empty 1: The Start command must be issued by software to perform data transfer. Bit 15 of Configuration register is used to issue Start command. This bit must be set whenever TXFIFO is filled with new data. NOTE: The driver will set the Manual Start Enable bit in Configuration Register, if Manual Start option is selected. Software will issue Manual Start command whenever TXFIFO is filled with data. When there is no further data, driver will clear the Manual Start Enable bit.
#define	XSPIPS_MASTER_OPTION 0x1
#define	XSPIPS_CLK_ACTIVE_LOW_OPTION 0x2
#define	XSPIPS_CLK_PHASE_1_OPTION 0x4
#define	XSPIPS_DECODE_SSELECT_OPTION 0x8
#define	XSPIPS_FORCE_SSELECT_OPTION 0x10
#define	XSPIPS_MANUAL_START_OPTION 0x20
SPI Clock Prescaler options
The SPI Clock Prescaler Configuration bits are used to program master mode bit rate. The bit rate can be programmed in divide-by-two decrements from pclk/4 to pclk/256.
#define	XSPIPS_CLK_PRESCALE_4 0x01
#define	XSPIPS_CLK_PRESCALE_8 0x02
#define	XSPIPS_CLK_PRESCALE_16 0x03
#define	XSPIPS_CLK_PRESCALE_32 0x04
#define	XSPIPS_CLK_PRESCALE_64 0x05
#define	XSPIPS_CLK_PRESCALE_128 0x06
#define	XSPIPS_CLK_PRESCALE_256 0x07
Callback events
These constants specify the handler events that are passed to a handler from the driver. These constants are not bit masks such that only one will be passed at a time to the handler.
#define	XSPIPS_EVENT_MODE_FAULT 1
#define	XSPIPS_EVENT_TRANSFER_DONE 2
#define	XSPIPS_EVENT_TRANSMIT_UNDERRUN 3
#define	XSPIPS_EVENT_RECEIVE_OVERRUN 4
Typedefs
typedef void(*	XSpiPs_StatusHandler )(void *CallBackRef, u32 StatusEvent, unsigned ByteCount)
Functions
XSpiPs_Config *	XSpiPs_LookupConfig (u16 DeviceId)
int	XSpiPs_CfgInitialize (XSpiPs InstancePtr, XSpiPs_Config Config, u32 EffectiveAddr)
void	XSpiPs_Reset (XSpiPs *InstancePtr)
int	XSpiPs_Transfer (XSpiPs InstancePtr, u8 SendBufPtr, u8 *RecvBufPtr, unsigned ByteCount)
int	XSpiPs_PolledTransfer (XSpiPs InstancePtr, u8 SendBufPtr, u8 *RecvBufPtr, unsigned ByteCount)
void	XSpiPs_SetStatusHandler (XSpiPs InstancePtr, void CallBackRef, XSpiPs_StatusHandler FuncPtr)
void	XSpiPs_InterruptHandler (void *InstancePtr)
void	XSpiPs_Abort (XSpiPs *InstancePtr)
int	XSpiPs_SetSlaveSelect (XSpiPs *InstancePtr, u8 SelectValue)
u8	XSpiPs_GetSlaveSelect (XSpiPs *InstancePtr)
int	XSpiPs_SelfTest (XSpiPs *InstancePtr)
int	XSpiPs_SetOptions (XSpiPs *InstancePtr, u32 Options)
u32	XSpiPs_GetOptions (XSpiPs *InstancePtr)
int	XSpiPs_SetClkPrescaler (XSpiPs *InstancePtr, u8 Prescaler)
u8	XSpiPs_GetClkPrescaler (XSpiPs *InstancePtr)
int	XSpiPs_SetDelays (XSpiPs *InstancePtr, u8 DelayNss, u8 DelayBtwn, u8 DelayAfter, u8 DelayInit)
void	XSpiPs_GetDelays (XSpiPs InstancePtr, u8 DelayNss, u8 DelayBtwn, u8 DelayAfter, u8 *DelayInit)

Detailed Description

Define Documentation

#define XSPIPS_CLK_ACTIVE_LOW_OPTION 0x2

Active Low Clock option

#define XSPIPS_CLK_PHASE_1_OPTION 0x4

Clock Phase one option

#define XSPIPS_CLK_PRESCALE_128 0x06

PCLK/128 Prescaler

#define XSPIPS_CLK_PRESCALE_16 0x03

PCLK/16 Prescaler

#define XSPIPS_CLK_PRESCALE_256 0x07

PCLK/256 Prescaler

#define XSPIPS_CLK_PRESCALE_32 0x04

PCLK/32 Prescaler

#define XSPIPS_CLK_PRESCALE_4 0x01

PCLK/4 Prescaler

#define XSPIPS_CLK_PRESCALE_64 0x05

PCLK/64 Prescaler

#define XSPIPS_CLK_PRESCALE_8 0x02

PCLK/8 Prescaler

#define XSPIPS_DECODE_SSELECT_OPTION 0x8

Select 16 slaves Option

#define XSpiPs_Disable ( InstancePtr ) XSpiPs_Out32((InstancePtr->Config.BaseAddress) + XSPIPS_ER_OFFSET, 0)

Disable the device.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: None.

Note:: C-Style signature: void XSpiPs_Disable(u32 *InstancePtr)

#define XSpiPs_Enable ( InstancePtr )

Value:

XSpiPs_Out32((InstancePtr->Config.BaseAddress) + XSPIPS_ER_OFFSET, \
                XSPIPS_ER_ENABLE_MASK)

Enable the device and uninhibit master transactions.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: None.

Note:: C-Style signature: void XSpiPs_Enable(u32 *InstancePtr)

#define XSPIPS_EVENT_MODE_FAULT 1

Mode fault error

#define XSPIPS_EVENT_RECEIVE_OVERRUN 4

Receive data loss because RX FIFO full

#define XSPIPS_EVENT_TRANSFER_DONE 2

Transfer done

#define XSPIPS_EVENT_TRANSMIT_UNDERRUN 3

TX FIFO empty

#define XSPIPS_FORCE_SSELECT_OPTION 0x10

Force Slave Select

#define XSpiPs_GetRXWatermark ( InstancePtr ) XSpiPs_In32((InstancePtr->Config.BaseAddress) + XSPIPS_RXWR_OFFSET)

Get the contents of the receive FIFO watermark register. Use the XSPIPS_RXWR_* constants defined xspips_hw.h to interpret the bit-mask returned.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: A 8-bit value representing the contents of the RXWR register.

Note:: C-Style signature: u32 XSpiPs_GetRXWatermark(u32 *InstancePtr)

#define XSpiPs_GetSlaveIdle ( InstancePtr )

Value:

XSpiPs_In32(((InstancePtr)->Config.BaseAddress) +               \
        XSPIPS_SICR_OFFSET)

Get the contents of the slave idle count register. Use the XSPIPS_SICR_* constants defined in xspips_hw.h to interpret the bit-mask returned.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: 8-bit value representing the contents of the SIC register.

Note:: C-Style signature: u32 XSpiPs_GetSlaveIdle(XSpiPs *InstancePtr)

#define XSpiPs_GetTXWatermark ( InstancePtr ) XSpiPs_In32((InstancePtr->Config.BaseAddress) + XSPIPS_TXWR_OFFSET)

Get the contents of the transmit FIFO watermark register. Use the XSPIPS_TXWR_* constants defined xspips_hw.h to interpret the bit-mask returned.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: 8-bit value representing the contents of the TXWR register.

Note:: C-Style signature: u32 XSpiPs_GetTXWatermark(u32 *InstancePtr)

#define XSPIPS_H

#define XSpiPs_IsDecodeSSelect ( InstancePtr )

Value:

((XSpiPs_GetOptions(InstancePtr) & \
                  XSPIPS_DECODE_SSELECT_OPTION) ? TRUE : FALSE)

#define XSpiPs_IsManualChipSelect ( InstancePtr )

Value:

((XSpiPs_GetOptions(InstancePtr) & \
                  XSPIPS_FORCE_SSELECT_OPTION) ? TRUE : FALSE)

#define XSpiPs_IsManualStart ( InstancePtr )

Value:

((XSpiPs_GetOptions(InstancePtr) & \
                  XSPIPS_MANUAL_START_OPTION) ? TRUE : FALSE)

#define XSpiPs_IsMaster ( InstancePtr )

Value:

((XSpiPs_GetOptions(InstancePtr) & \
                  XSPIPS_MASTER_OPTION) ? TRUE : FALSE)

#define XSPIPS_MANUAL_START_OPTION 0x20

Manual Start mode option

#define XSPIPS_MASTER_OPTION 0x1

Master mode option

#define XSpiPs_SetRXWatermark	(	InstancePtr,
		RegisterValue		)

Value:

XSpiPs_Out32(((InstancePtr)->Config.BaseAddress) +              \
                XSPIPS_RXWR_OFFSET, (RegisterValue))

Set the contents of the receive FIFO watermark register.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	RegisterValue	is the value to be written, valid values are 1-128.

Returns:: None.

Note:: C-Style signature: void XSpiPs_SetRXWatermark(XSpiPs *InstancePtr, u32 RegisterValue)

#define XSpiPs_SetSlaveIdle	(	InstancePtr,
		RegisterValue		)

Value:

XSpiPs_Out32(((InstancePtr)->Config.BaseAddress) +      \
                XSPIPS_SICR_OFFSET, (RegisterValue))

Set the contents of the slave idle count register.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	RegisterValue	is the value to be writen, valid values are 0-255.

Returns:: None

Note:: C-Style signature: void XSpiPs_SetSlaveIdle(XSpiPs *InstancePtr, u32 RegisterValue)

#define XSpiPs_SetTXWatermark	(	InstancePtr,
		RegisterValue		)

Value:

XSpiPs_Out32(((InstancePtr)->Config.BaseAddress) +              \
                XSPIPS_TXWR_OFFSET, (RegisterValue))

Set the contents of the transmit FIFO watermark register.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	RegisterValue	is the value to be written, valid values are 1-128.

Returns:: None.

Note:: C-Style signature: void XSpiPs_SetTXWatermark(XSpiPs *InstancePtr, u32 RegisterValue)

Typedef Documentation

typedef void(* XSpiPs_StatusHandler)(void *CallBackRef, u32 StatusEvent, unsigned ByteCount)

The handler data type allows the user to define a callback function to handle the asynchronous processing for the SPI device. The application using this driver is expected to define a handler of this type to support interrupt driven mode. The handler executes in an interrupt context, so only minimal processing should be performed.

Parameters:

	CallBackRef	is the callback reference passed in by the upper layer when setting the callback functions, and passed back to the upper layer when the callback is invoked. Its type is not important to the driver, so it is a void pointer.
	StatusEvent	holds one or more status events that have occurred. See the XSpiPs_SetStatusHandler() for details on the status events that can be passed in the callback.
	ByteCount	indicates how many bytes of data were successfully transferred. This may be less than the number of bytes requested if the status event indicates an error.

Function Documentation

void XSpiPs_Abort ( XSpiPs * InstancePtr )

Aborts a transfer in progress by disabling the device and resetting the FIFOs if present. The byte counts are cleared, the busy flag is cleared, and mode fault is cleared.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: None.

Note:

This function does a read/modify/write of the Config register. The user of this function needs to take care of critical sections.

int XSpiPs_CfgInitialize	(	XSpiPs *	InstancePtr,
		XSpiPs_Config *	ConfigPtr,
		u32	EffectiveAddr
	)

Initializes a specific XSpiPs instance such that the driver is ready to use.

The state of the device after initialization is:

Device is disabled
Slave mode
Active high clock polarity
Clock phase 0

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	ConfigPtr	is a reference to a structure containing information about a specific SPI device. This function initializes an InstancePtr object for a specific device specified by the contents of Config. This function can initialize multiple instance objects with the use of multiple calls giving different Config information on each call.
	EffectiveAddr	is the device base address in the virtual memory address space. The caller is responsible for keeping the address mapping from EffectiveAddr to the device physical base address unchanged once this function is invoked. Unexpected errors may occur if the address mapping changes after this function is called. If address translation is not used, use ConfigPtr->Config.BaseAddress for this device.

Returns:

XST_SUCCESS if successful.
XST_DEVICE_IS_STARTED if the device is already started. It must be stopped to re-initialize.

Note:: None.

u8 XSpiPs_GetClkPrescaler ( XSpiPs * InstancePtr )

This function gets the clock prescaler of an SPI device.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: The prescaler value.

Note:: None.

void XSpiPs_GetDelays	(	XSpiPs *	InstancePtr,
		u8 *	DelayNss,
		u8 *	DelayBtwn,
		u8 *	DelayAfter,
		u8 *	DelayInit
	)

This function gets the delay settings for an SPI device. The delay register controls the Delay Between Transfers, Delay After Transfers, and the Delay Initially. The default value is 0x0.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	DelayNss	is a pointer to the delay for which the chip select outputs will be de-asserted between words when CPHA=0.
	DelayBtwn	is a pointer to the Delay Between transfers value. This is a return parameter.
	DelayAfter	is a pointer to the Delay After transfer value. This is a return parameter.
	DelayInit	is a pointer to the Delay Initially value. This is a return parameter.

Returns:: None.

Note:: None.

u32 XSpiPs_GetOptions ( XSpiPs * InstancePtr )

This function gets the options for the SPI device. The options control how the device behaves relative to the SPI bus.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:

Options contains the specified options currently set. This is a bit value where a 1 means the option is on, and a 0 means the option is off. See the bit definitions named XSPIPS_*_OPTIONS in file xspips.h.

Note:: None.

u8 XSpiPs_GetSlaveSelect ( XSpiPs * InstancePtr )

Gets the current slave select setting for the SPI device.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: The slave number selected (starting from 0).

Note:: None.

void XSpiPs_InterruptHandler ( void * InstancePtr )

The interrupt handler for SPI interrupts. This function must be connected by the user to an interrupt controller.

The interrupts that are handled are:

Mode Fault Error. This interrupt is generated if this device is selected as a slave when it is configured as a master. The driver aborts any data transfer that is in progress by resetting FIFOs (if present) and resetting its buffer pointers. The upper layer software is informed of the error.

Data Transmit Register (FIFO) Empty. This interrupt is generated when the transmit register or FIFO is empty. The driver uses this interrupt during a transmission to continually send/receive data until the transfer is done.

Data Transmit Register (FIFO) Underflow. This interrupt is generated when the SPI device, when configured as a slave, attempts to read an empty DTR/FIFO. An empty DTR/FIFO usually means that software is not giving the device data in a timely manner. No action is taken by the driver other than to inform the upper layer software of the error.

Data Receive Register (FIFO) Overflow. This interrupt is generated when the SPI device attempts to write a received byte to an already full DRR/FIFO. A full DRR/FIFO usually means software is not emptying the data in a timely manner. No action is taken by the driver other than to inform the upper layer software of the error.

Slave Mode Fault Error. This interrupt is generated if a slave device is selected as a slave while it is disabled. No action is taken by the driver other than to inform the upper layer software of the error.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: None.

Note:

The slave select register is being set to deselect the slave when a transfer is complete. This is being done regardless of whether it is a slave or a master since the hardware does not drive the slave select as a slave.

XSpiPs_Config* XSpiPs_LookupConfig ( u16 DeviceId )

Looks up the device configuration based on the unique device ID. A table contains the configuration info for each device in the system.

Parameters:

DeviceId

contains the ID of the device to look up the configuration for.

Returns:

A pointer to the configuration found or NULL if the specified device ID was not found. See xspips.h for the definition of XSpiPs_Config.

Note:: None.

int XSpiPs_PolledTransfer	(	XSpiPs *	InstancePtr,
		u8 *	SendBufPtr,
		u8 *	RecvBufPtr,
		unsigned	ByteCount
	)

Transfers specified data on the SPI bus in polled mode.

The caller has the option of providing two different buffers for send and receive, or one buffer for both send and receive, or no buffer for receive. The receive buffer must be at least as big as the send buffer to prevent unwanted memory writes. This implies that the byte count passed in as an argument must be the smaller of the two buffers if they differ in size. Here are some sample usages:

   XSpiPs_PolledTransfer(InstancePtr, SendBuf, RecvBuf, ByteCount)
	The caller wishes to send and receive, and provides two different
	buffers for send and receive.

   XSpiPs_PolledTransfer(InstancePtr, SendBuf, NULL, ByteCount)
	The caller wishes only to send and does not care about the received
	data. The driver ignores the received data in this case.

   XSpiPs_PolledTransfer(InstancePtr, SendBuf, SendBuf, ByteCount)
	The caller wishes to send and receive, but provides the same buffer
	for doing both. The driver sends the data and overwrites the send
	buffer with received data as it transfers the data.

   XSpiPs_PolledTransfer(InstancePtr, RecvBuf, RecvBuf, ByteCount)
	The caller wishes to only receive and does not care about sending
	data.  In this case, the caller must still provide a send buffer, but
	it can be the same as the receive buffer if the caller does not care
	what it sends.  The device must send N bytes of data if it wishes to
	receive N bytes of data.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	SendBufPtr	is a pointer to a buffer of data for sending. This buffer must not be NULL.
	RecvBufPtr	is a pointer to a buffer for received data. This argument can be NULL if do not care about receiving.
	ByteCount	contains the number of bytes to send/receive. The number of bytes received always equals the number of bytes sent.

Returns:

XST_SUCCESS if the buffers are successfully handed off to the device for transfer.
XST_DEVICE_BUSY indicates that a data transfer is already in progress. This is determined by the driver.

Note:

This function is not thread-safe. The higher layer software must ensure that no two threads are transferring data on the SPI bus at the same time.

void XSpiPs_Reset ( XSpiPs * InstancePtr )

Resets the SPI device. Reset must only be called after the driver has been initialized. The configuration of the device after reset is the same as its configuration after initialization. Any data transfer that is in progress is aborted.

The upper layer software is responsible for re-configuring (if necessary) and restarting the SPI device after the reset.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:: None.

Note:: None.

int XSpiPs_SelfTest ( XSpiPs * InstancePtr )

Runs a self-test on the driver/device. The self-test is destructive in that a reset of the device is performed in order to check the reset values of the registers and to get the device into a known state.

Upon successful return from the self-test, the device is reset.

Parameters:

InstancePtr

is a pointer to the XSpiPs instance.

Returns:

XST_SUCCESS if successful
XST_REGISTER_ERROR indicates a register did not read or write correctly.

Note:: None.

int XSpiPs_SetClkPrescaler	(	XSpiPs *	InstancePtr,
		u8	Prescaler
	)

This function sets the clock prescaler for an SPI device. The device must be idle rather than busy transferring data before setting these device options.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	Prescaler	is the value that determine how much the clock should be divided by. Use the XSPIPS_CLK_PRESCALE_* constants defined in xspips.h for this setting.

Returns:

XST_SUCCESS if options are successfully set.
XST_DEVICE_BUSY if the device is currently transferring data. The transfer must complete or be aborted before setting options.

Note:: This function is not thread-safe.

int XSpiPs_SetDelays	(	XSpiPs *	InstancePtr,
		u8	DelayNss,
		u8	DelayBtwn,
		u8	DelayAfter,
		u8	DelayInit
	)

This function sets the delay register for the SPI device driver. The delay register controls the Delay Between Transfers, Delay After Transfers, and the Delay Initially. The default value is 0x0. The range of each delay value is 0-255.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	DelayNss	is the delay for which the chip select outputs will be de-asserted between words when CPHA=0.
	DelayBtwn	is the delay between one Slave Select being de-activated and the activation of another slave. The delay is the number of master clock periods given by DelayBtwn + 2.
	DelayAfter	define the delay between the last bit of the current byte transfer and the first bit of the next byte transfer. The delay in number of master clock periods is given as: CPHA=0:DelayInit+DelayAfter+3 CPHA=1:DelayAfter+1
	DelayInit	is the delay between asserting the slave select signal and the first bit transfer. The delay int number of master clock periods is DelayInit+1.

Returns:

XST_SUCCESS if delays are successfully set.
XST_DEVICE_BUSY if the device is currently transferring data. The transfer must complete or be aborted before setting options.

Note:: None.

int XSpiPs_SetOptions	(	XSpiPs *	InstancePtr,
		u32	Options
	)

This function sets the options for the SPI device driver. The options control how the device behaves relative to the SPI bus. The device must be idle rather than busy transferring data before setting these device options.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	Options	contains the specified options to be set. This is a bit mask where a 1 means to turn the option on, and a 0 means to turn the option off. One or more bit values may be contained in the mask. See the bit definitions named XSPIPS_*_OPTIONS in the file xspips.h.

Returns:

XST_SUCCESS if options are successfully set.
XST_DEVICE_BUSY if the device is currently transferring data. The transfer must complete or be aborted before setting options.

Note:: This function is not thread-safe.

int XSpiPs_SetSlaveSelect	(	XSpiPs *	InstancePtr,
		u8	SlaveSel
	)

Selects or deselect the slave with which the master communicates. This setting affects the SPI_ss_outN signals. The behavior depends on the setting of the CR_SSDECEN bit. If CR_SSDECEN is 0, the SPI_ss_outN bits will be output with a single signal low. If CR_SSDECEN is 1, the SPI_ss_outN bits will reflect the value set.

The user is not allowed to deselect the slave while a transfer is in progress. If no transfer is in progress, the user can select a new slave, which implicitly deselects the current slave. In order to explicitly deselect the current slave, a value of all 1's, 0x0F can be passed in as the argument to the function.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	SlaveSel	is the slave number to be selected. Normally, 3 slaves can be selected with values 0-2. In case, 3-8 decode option is set, then upto 8 slaves can be selected. Only one slave can be selected at a time.

Returns:

XST_SUCCESS if the slave is selected or deselected successfully.
XST_DEVICE_BUSY if a transfer is in progress, slave cannot be changed.

Note:

This function only sets the slave which will be selected when a transfer occurs. The slave is not selected when the SPI is idle. The slave select has no affect when the device is configured as a slave.

void XSpiPs_SetStatusHandler	(	XSpiPs *	InstancePtr,
		void *	CallBackRef,
		XSpiPs_StatusHandler	FuncPtr
	)

Sets the status callback function, the status handler, which the driver calls when it encounters conditions that should be reported to upper layer software. The handler executes in an interrupt context, so it must minimize the amount of processing performed. One of the following status events is passed to the status handler.

 XST_SPI_MODE_FAULT		A mode fault error occurred, meaning the device
				is selected as slave while being a master.

 XST_SPI_TRANSFER_DONE		The requested data transfer is done

 XST_SPI_TRANSMIT_UNDERRUN	As a slave device, the master clocked data
				but there were none available in the transmit
				register/FIFO. This typically means the slave
				application did not issue a transfer request
				fast enough, or the processor/driver could not
				fill the transmit register/FIFO fast enough.

 XST_SPI_RECEIVE_OVERRUN	The SPI device lost data. Data was received
				but the receive data register/FIFO was full.

 XST_SPI_SLAVE_MODE_FAULT	A slave SPI device was selected as a slave
				while it was disabled. This indicates the
				master is already transferring data (which is
				being dropped until the slave application
				issues a transfer).

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	CallBackRef	is the upper layer callback reference passed back when the callback function is invoked.
	FuncPtr	is the pointer to the callback function.

Returns:: None.

Note:

The handler is called within interrupt context, so it should do its work quickly and queue potentially time-consuming work to a task-level thread.

int XSpiPs_Transfer	(	XSpiPs *	InstancePtr,
		u8 *	SendBufPtr,
		u8 *	RecvBufPtr,
		unsigned	ByteCount
	)

Transfers specified data on the SPI bus. If the SPI device is configured as a master, this function initiates bus communication and sends/receives the data to/from the selected SPI slave. If the SPI device is configured as a slave, this function prepares the buffers to be sent/received when selected by a master. For every byte sent, a byte is received. This function should be used to perform interrupt based transfers.

The caller has the option of providing two different buffers for send and receive, or one buffer for both send and receive, or no buffer for receive. The receive buffer must be at least as big as the send buffer to prevent unwanted memory writes. This implies that the byte count passed in as an argument must be the smaller of the two buffers if they differ in size. Here are some sample usages:

   XSpiPs_Transfer(InstancePtr, SendBuf, RecvBuf, ByteCount)
	The caller wishes to send and receive, and provides two different
	buffers for send and receive.

   XSpiPs_Transfer(InstancePtr, SendBuf, NULL, ByteCount)
	The caller wishes only to send and does not care about the received
	data. The driver ignores the received data in this case.

   XSpiPs_Transfer(InstancePtr, SendBuf, SendBuf, ByteCount)
	The caller wishes to send and receive, but provides the same buffer
	for doing both. The driver sends the data and overwrites the send
	buffer with received data as it transfers the data.

   XSpiPs_Transfer(InstancePtr, RecvBuf, RecvBuf, ByteCount)
	The caller wishes to only receive and does not care about sending
	data.  In this case, the caller must still provide a send buffer, but
	it can be the same as the receive buffer if the caller does not care
	what it sends.  The device must send N bytes of data if it wishes to
	receive N bytes of data.

Although this function takes entire buffers as arguments, the driver can only transfer a limited number of bytes at a time, limited by the size of the FIFO. A call to this function only starts the transfer, then subsequent transfers of the data is performed by the interrupt service routine until the entire buffer has been transferred. The status callback function is called when the entire buffer has been sent/received.

This function is non-blocking. As a master, the SetSlaveSelect function must be called prior to this function.

Parameters:

	InstancePtr	is a pointer to the XSpiPs instance.
	SendBufPtr	is a pointer to a buffer of data for sending. This buffer must not be NULL.
	RecvBufPtr	is a pointer to a buffer for received data. This argument can be NULL if do not care about receiving.
	ByteCount	contains the number of bytes to send/receive. The number of bytes received always equals the number of bytes sent.

Returns:

XST_SUCCESS if the buffers are successfully handed off to the device for transfer.
XST_DEVICE_BUSY indicates that a data transfer is already in progress. This is determined by the driver.

Note:

This function is not thread-safe. The higher layer software must ensure that no two threads are transferring data on the SPI bus at the same time.

Xilinx Processor IP Library

xspips.h File Reference

Classes

Defines

Typedefs

Functions

Detailed Description

Define Documentation

Typedef Documentation

Function Documentation