SPI_Serial_Peripheral_Interface_api

Functions
void	SPIEnable (unsigned long ulBase)
void	SPIDisable (unsigned long ulBase)
void	SPIDmaEnable (unsigned long ulBase, unsigned long ulFlags)
void	SPIDmaDisable (unsigned long ulBase, unsigned long ulFlags)
void	SPIReset (unsigned long ulBase)
void	SPIConfigSetExpClk (unsigned long ulBase, unsigned long ulSPIClk, unsigned long ulBitRate, unsigned long ulMode, unsigned long ulSubMode, unsigned long ulConfig)
long	SPIDataGetNonBlocking (unsigned long ulBase, unsigned long *pulData)
void	SPIDataGet (unsigned long ulBase, unsigned long *pulData)
long	SPIDataPutNonBlocking (unsigned long ulBase, unsigned long ulData)
void	SPIDataPut (unsigned long ulBase, unsigned long ulData)
void	SPIFIFOEnable (unsigned long ulBase, unsigned long ulFlags)
void	SPIFIFODisable (unsigned long ulBase, unsigned long ulFlags)
void	SPIFIFOLevelSet (unsigned long ulBase, unsigned long ulTxLevel, unsigned long ulRxLevel)
void	SPIFIFOLevelGet (unsigned long ulBase, unsigned long *pulTxLevel, unsigned long *pulRxLevel)
void	SPIWordCountSet (unsigned long ulBase, unsigned long ulWordCount)
void	SPIIntRegister (unsigned long ulBase, void(*pfnHandler)(void))
void	SPIIntUnregister (unsigned long ulBase)
void	SPIIntEnable (unsigned long ulBase, unsigned long ulIntFlags)
void	SPIIntDisable (unsigned long ulBase, unsigned long ulIntFlags)
unsigned long	SPIIntStatus (unsigned long ulBase, tBoolean bMasked)
void	SPIIntClear (unsigned long ulBase, unsigned long ulIntFlags)
void	SPICSEnable (unsigned long ulBase)
void	SPICSDisable (unsigned long ulBase)
long	SPITransfer (unsigned long ulBase, unsigned char *ucDout, unsigned char *ucDin, unsigned long ulCount, unsigned long ulFlags)

Detailed Description

Function Documentation

void SPIConfigSetExpClk	(	unsigned long	ulBase,
		unsigned long	ulSPIClk,
		unsigned long	ulBitRate,
		unsigned long	ulMode,
		unsigned long	ulSubMode,
		unsigned long	ulConfig
	)

Sets the configuration of a SPI module

Parameters

ulBase	is the base address of the SPI module
ulSPIClk	is the rate of clock supplied to the SPI module.
ulBitRate	is the desired bit rate.(master mode)
ulMode	is the mode of operation.
ulSubMode	is one of the valid sub-modes.
ulConfig	is logical OR of configuration paramaters.

This function configures SPI port for operation in specified sub-mode and required bit rated as specified by ulMode and ulBitRate parameters respectively.

The SPI module can operate in either master or slave mode. The parameter ulMode can be one of the following -SPI_MODE_MASTER -SPI_MODE_SLAVE

The SPI module supports 4 sub modes based on SPI clock polarity and phase.

Polarity Phase  Sub-Mode
  0       0        0
  0       1        1
  1       0        2
  1       1        3

Required sub mode can be select by setting ulSubMode parameter to one of the following

• SPI_SUB_MODE_0
• SPI_SUB_MODE_1
• SPI_SUB_MODE_2
• SPI_SUB_MODE_3

The parameter ulConfig is logical OR of five values: the word length, active level for chip select, software or hardware controled chip select, 3 or 4 pin mode and turbo mode. mode.

SPI support 8, 16 and 32 bit word lengths defined by:-

• SPI_WL_8
• SPI_WL_16
• SPI_WL_32

Active state of Chip[ Selece can be defined by:-

• SPI_CS_ACTIVELOW
• SPI_CS_ACTIVEHIGH

SPI chip select can be configured to be controlled either by hardware or software:-

• SPI_SW_CS
• SPI_HW_CS

The module can work in 3 or 4 pin mode defined by:-

• SPI_3PIN_MODE
• SPI_4PIN_MODE

Turbo mode can be set on or turned off using:-

• SPI_TURBO_MODE_ON
• SPI_TURBO_MODE_OFF

Returns

None.

void SPICSDisable

(

unsigned long

ulBase

)

Disables the chip select in software controlled mode

Parameters

ulBase

is the base address of the SPI module.

This function disables the Chip select in software controlled mode. The active state of CS will depend on the configuration done via sa SPIConfigSetExpClk().

Returns

None.

void SPICSEnable

(

unsigned long

ulBase

)

Enables the chip select in software controlled mode

Parameters

ulBase

is the base address of the SPI module.

This function enables the Chip select in software controlled mode. The active state of CS will depend on the configuration done via

See also

SPIConfigExpClkSet().

Returns

None.

void SPIDataGet	(	unsigned long	ulBase,
		unsigned long *	pulData
	)

Waits for the word to be received on the specified port.

Parameters

ulBase	is the base address of the SPI module.
pulData	is pointer to receive data variable.

This function gets a SPI word from the receive FIFO for the specified port. If there is no word available, this function waits until a word is received before returning.

Returns

Returns the word read from the specified port, cast as an unsigned long.

long SPIDataGetNonBlocking	(	unsigned long	ulBase,
		unsigned long *	pulData
	)

Receives a word from the specified port.

Parameters

ulBase	is the base address of the SPI module.
pulData	is pointer to receive data variable.

This function gets a SPI word from the receive FIFO for the specified port.

Returns

Returns the number of elements read from the receive FIFO.

void SPIDataPut	(	unsigned long	ulBase,
		unsigned long	ulData
	)

Waits until the word is transmitted on the specified port.

Parameters

ulBase	is the base address of the SPI module
ulData	is data to be transmitted.

This function transmits a SPI word on the transmit FIFO for the specified port. This function waits until the space is available on transmit FIFO

Returns

None

long SPIDataPutNonBlocking	(	unsigned long	ulBase,
		unsigned long	ulData
	)

Transmits a word on the specified port.

Parameters

ulBase	is the base address of the SPI module
ulData	is data to be transmitted.

This function transmits a SPI word on the transmit FIFO for the specified port.

Returns

Returns the number of elements written to the transmit FIFO.

void SPIDisable

(

unsigned long

ulBase

)

Disables the transmitting and receiving.

Parameters

ulBase

is the base address of the SPI module

This function disables the SPI channel for transmitting and receiving.

Returns

None

void SPIDmaDisable	(	unsigned long	ulBase,
		unsigned long	ulFlags
	)

Disables the SPI DMA operation for transmitting and/or receving.

Parameters

ulBase	is the base address of the SPI module
ulFlags	selectes the DMA signal for transmit and/or receive.

This function disables transmit and/or receive DMA request based on the ulFlags parameter.

The parameter ulFlags is the logical OR of one or more of the following :

• SPI_RX_DMA
• SPI_TX_DMA

Returns

None.

void SPIDmaEnable	(	unsigned long	ulBase,
		unsigned long	ulFlags
	)

Enables the SPI DMA operation for transmitting and/or receving.

Parameters

ulBase	is the base address of the SPI module
ulFlags	selectes the DMA signal for transmit and/or receive.

This function enables transmit and/or receive DMA request based on the ulFlags parameter.

The parameter ulFlags is the logical OR of one or more of the following :

• SPI_RX_DMA
• SPI_TX_DMA

Returns

None.

void SPIEnable

(

unsigned long

ulBase

)

Enables transmitting and receiving.

Parameters

ulBase

is the base address of the SPI module

This function enables the SPI channel for transmitting and receiving.

Returns

None

void SPIFIFODisable	(	unsigned long	ulBase,
		unsigned long	ulFlags
	)

Disables the transmit and/or receive FIFOs.

Parameters

ulBase	is the base address of the SPI module
ulFlags	selects the FIFO(s) to be enabled

This function disables transmit and/or receive FIFOs. as specified by ulFlags. The parameter ulFlags shoulde be logical OR of one or more of the following:

• SPI_TX_FIFO
• SPI_RX_FIFO

Returns

None.

void SPIFIFOEnable	(	unsigned long	ulBase,
		unsigned long	ulFlags
	)

Enables the transmit and/or receive FIFOs.

Parameters

ulBase	is the base address of the SPI module
ulFlags	selects the FIFO(s) to be enabled

This function enables the transmit and/or receive FIFOs as specified by ulFlags. The parameter ulFlags shoulde be logical OR of one or more of the following:

• SPI_TX_FIFO
• SPI_RX_FIFO

Returns

None.

void SPIFIFOLevelGet	(	unsigned long	ulBase,
		unsigned long *	pulTxLevel,
		unsigned long *	pulRxLevel
	)

Gets the FIFO level at which DMA requests or interrupts are generated.

Parameters

ulBase	is the base address of the SPI module
pulTxLevel	is a pointer to storage for the transmit FIFO level
pulRxLevel	is a pointer to storage for the receive FIFO level

This function gets the FIFO level at which DMA requests or interrupts are generated.

Returns

None.

void SPIFIFOLevelSet	(	unsigned long	ulBase,
		unsigned long	ulTxLevel,
		unsigned long	ulRxLevel
	)

Sets the FIFO level at which DMA requests or interrupts are generated.

Parameters

ulBase	is the base address of the SPI module
ulTxLevel	is the Almost Empty Level for transmit FIFO.
ulRxLevel	is the Almost Full Level for the receive FIFO.

This function Sets the FIFO level at which DMA requests or interrupts are generated.

Returns

None.

void SPIIntClear	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Clears SPI interrupt sources.

Parameters

ulBase	is the base address of the SPI module
ulIntFlags	is a bit mask of the interrupt sources to be cleared.

The specified SPI interrupt sources are cleared, so that they no longer assert. This function must be called in the interrupt handler to keep the interrupt from being recognized again immediately upon exit.

The ulIntFlags parameter has the same definition as the ulIntFlags parameter to SPIIntEnable().

Returns

None.

void SPIIntDisable	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Disables individual SPI interrupt sources.

Parameters

ulBase	is the base address of the SPI module
ulIntFlags	is the bit mask of the interrupt sources to be disabled.

This function disables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

The ulIntFlags parameter has the same definition as the ulIntFlags parameter to SPIIntEnable().

Returns

None.

void SPIIntEnable	(	unsigned long	ulBase,
		unsigned long	ulIntFlags
	)

Enables individual SPI interrupt sources.

Parameters

ulBase	is the base address of the SPI module
ulIntFlags	is the bit mask of the interrupt sources to be enabled.

This function enables the indicated SPI interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

The ulIntFlags parameter is the logical OR of any of the following:

• SPI_INT_DMATX
• SPI_INT_DMARX
• SPI_INT_EOW
• SPI_INT_RX_OVRFLOW
• SPI_INT_RX_FULL
• SPI_INT_TX_UDRFLOW
• SPI_INT_TX_EMPTY

Returns

None.

void SPIIntRegister	(	unsigned long	ulBase,
		void(*)(void)	pfnHandler
	)

Registers an interrupt handler for a SPI interrupt.

Parameters

ulBase	is the base address of the SPI module
pfnHandler	is a pointer to the function to be called when the SPI interrupt occurs.

This function does the actual registering of the interrupt handler. This function enables the global interrupt in the interrupt controller; specific SPI interrupts must be enabled via SPIIntEnable(). It is the interrupt handler's responsibility to clear the interrupt source.

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

unsigned long SPIIntStatus	(	unsigned long	ulBase,
		tBoolean	bMasked
	)

Gets the current interrupt status.

Parameters

ulBase	is the base address of the SPI module
bMasked	is false if the raw interrupt status is required and true if the masked interrupt status is required.

This function returns the interrupt status for the specified SPI. The status of interrupts that are allowed to reflect to the processor can be returned.

Returns

Returns the current interrupt status, enumerated as a bit field of values described in SPIIntEnable().

void SPIIntUnregister

(

unsigned long

ulBase

)

Unregisters an interrupt handler for a SPI interrupt.

Parameters

ulBase

is the base address of the SPI module

This function does the actual unregistering of the interrupt handler. It clears the handler to be called when a SPI interrupt occurs. This function also masks off the interrupt in the interrupt controller so that the interrupt handler no longer is called.

See also

IntRegister() for important information about registering interrupt handlers.

Returns

None.

void SPIReset

(

unsigned long

ulBase

)

Performs a software reset of the specified SPI module

Parameters

ulBase

is the base address of the SPI module

This function performs a software reset of the specified SPI module

Returns

None.

long SPITransfer	(	unsigned long	ulBase,
		unsigned char *	ucDout,
		unsigned char *	ucDin,
		unsigned long	ulCount,
		unsigned long	ulFlags
	)

Send/Receive data buffer over SPI channel

Parameters

ulBase	is the base address of SPI module
ucDout	is the pointer to Tx data buffer or 0.
ucDin	is pointer to Rx data buffer or 0
ulCount	is the size of data in bytes.
ulFlags	controlls chip select toggling.

This function transfers ulCount bytes of data over SPI channel. Since the API sends a SPI word at a time ulCount should be a multiple of word length set using SPIConfigSetExpClk().

If the ucDout parameter is set to 0, the function will send 0xFF over the SPI MOSI line.

If the ucDin parameter is set to 0, the function will ignore data on SPI MISO line.

The parameter ulFlags is logical OR of one or more of the following

• SPI_CS_ENABLE if CS needs to be enabled at start of transfer.
• SPI_CS_DISABLE if CS need to be disabled at the end of transfer.

This function will not return until data has been transmitted

Returns

Returns 0 on success, -1 otherwise.

void SPIWordCountSet	(	unsigned long	ulBase,
		unsigned long	ulWordCount
	)

Sets the word count.

Parameters

ulBase	is the base address of the SPI module
ulWordCount	is number of SPI words to be transmitted.

This function sets the word count, which is the number of SPI word to be transferred on channel when using the FIFO buffer.

Returns

None.