Functions
void	SSIConfigSetExpClk (uint32_t ui32Base, uint32_t ui32SSIClk, uint32_t ui32Protocol, uint32_t ui32Mode, uint32_t ui32BitRate, uint32_t ui32DataWidth)
	Configures the synchronous serial port. More...

static void	SSIEnable (uint32_t ui32Base)
	Enables the synchronous serial port. More...

static void	SSIDisable (uint32_t ui32Base)
	Disables the synchronous serial port. More...

void	SSIDataPut (uint32_t ui32Base, uint32_t ui32Data)
	Puts a data element into the SSI transmit FIFO. More...

int32_t	SSIDataPutNonBlocking (uint32_t ui32Base, uint32_t ui32Data)
	Puts a data element into the SSI transmit FIFO. More...

void	SSIDataGet (uint32_t ui32Base, uint32_t *pui32Data)
	Gets a data element from the SSI receive FIFO. More...

int32_t	SSIDataGetNonBlocking (uint32_t ui32Base, uint32_t *pui32Data)
	Gets a data element from the SSI receive FIFO. More...

static bool	SSIBusy (uint32_t ui32Base)
	Determines whether the SSI transmitter is busy or not. More...

static uint32_t	SSIStatus (uint32_t ui32Base)
	Get the status of the SSI data buffers. More...

void	SSIIntRegister (uint32_t ui32Base, void(*pfnHandler)(void))
	Registers an interrupt handler for the synchronous serial port. More...

void	SSIIntUnregister (uint32_t ui32Base)
	Unregisters an interrupt handler for the synchronous serial port. More...

static void	SSIIntEnable (uint32_t ui32Base, uint32_t ui32IntFlags)
	Enables individual SSI interrupt sources. More...

static void	SSIIntDisable (uint32_t ui32Base, uint32_t ui32IntFlags)
	Disables individual SSI interrupt sources. More...

static void	SSIIntClear (uint32_t ui32Base, uint32_t ui32IntFlags)
	Clears SSI interrupt sources. More...

static uint32_t	SSIIntStatus (uint32_t ui32Base, bool bMasked)
	Gets the current interrupt status. More...

static void	SSIDMAEnable (uint32_t ui32Base, uint32_t ui32DMAFlags)
	Enable SSI DMA operation. More...

static void	SSIDMADisable (uint32_t ui32Base, uint32_t ui32DMAFlags)
	Disable SSI DMA operation. More...

Detailed Description

Function Documentation

static bool SSIBusy ( uint32_t ui32Base )

inlinestatic

Determines whether the SSI transmitter is busy or not.

Allows the caller to determine whether all transmitted bytes have cleared the transmitter hardware. If false is returned, then the transmit FIFO is empty and all bits of the last transmitted word have left the hardware shift register.

Parameters

ui32Base is the base address of the SSI port.

Returns

Returns status of the SSI transmit buffer.

true : SSI is transmitting.
false : SSI transmissions are complete.

Definition at line 385 of file ssi.h.

void SSIConfigSetExpClk	(	uint32_t	ui32Base,
		uint32_t	ui32SSIClk,
		uint32_t	ui32Protocol,
		uint32_t	ui32Mode,
		uint32_t	ui32BitRate,
		uint32_t	ui32DataWidth
	)

Configures the synchronous serial port.

This function configures the synchronous serial port. It sets the SSI protocol, mode of operation, bit rate, and data width.

The ui32Protocol parameter defines the data frame format. The Motorola frame formats imply the following polarity and phase configurations:

Polarity Phase       Mode
  0       0   SSI_FRF_MOTO_MODE_0
  0       1   SSI_FRF_MOTO_MODE_1
  1       0   SSI_FRF_MOTO_MODE_2
  1       1   SSI_FRF_MOTO_MODE_3

The ui32Mode parameter defines the operating mode of the SSI module. The SSI module can operate as a master or slave; if a slave, the SSI can be configured to disable output on its serial output line.

The ui32BitRate parameter defines the bit rate for the SSI. This bit rate must satisfy the following clock ratio criteria:

Master mode : FSSI >= 2 * bit rate
Slave mode : FSSI >= 12 * bit rate

where FSSI is the frequency of the clock supplied to the SSI module.

The ui32DataWidth parameter defines the width of the data transfers, and can be a value between 4 and 16, inclusive.

Note: The peripheral clock is not necessarily the same as the processor clock. The frequency of the peripheral clock is set by the system control.

Parameters

ui32Base	specifies the SSI module base address.
ui32SSIClk	is the rate of the clock supplied to the SSI module.
ui32Protocol	specifies the data transfer protocol. The parameter can be one of the following values: SSI_FRF_MOTO_MODE_0 SSI_FRF_MOTO_MODE_1 SSI_FRF_MOTO_MODE_2 SSI_FRF_MOTO_MODE_3 SSI_FRF_TI SSI_FRF_NMW.
ui32Mode	specifies the mode of operation. The parameter can be one of the following values: SSI_MODE_MASTER SSI_MODE_SLAVE SSI_MODE_SLAVE_OD
ui32BitRate	specifies the clock rate.
ui32DataWidth	specifies number of bits transferred per frame. Must be a value between 4 and 16, both included.

Returns: None

Definition at line 70 of file ssi.c.

void SSIDataGet	(	uint32_t	ui32Base,
		uint32_t *	pui32Data
	)

Gets a data element from the SSI receive FIFO.

This function gets received data from the receive FIFO of the specified SSI module and places that data into the location specified by the pui32Data parameter.

Note: Only the lower N bits of the value written to pui32Data contain valid data, where N is the data width as configured by SSIConfigSetExpClk(). For example, if the interface is configured for 8-bit data width, only the lower 8 bits of the value written to pui32Data contain valid data.

Parameters

ui32Base	specifies the SSI module base address.
pui32Data	is a pointer to a storage location for data that was received over the SSI interface.

Returns: None

Definition at line 191 of file ssi.c.

int32_t SSIDataGetNonBlocking	(	uint32_t	ui32Base,
		uint32_t *	pui32Data
	)

Gets a data element from the SSI receive FIFO.

This function gets received data from the receive FIFO of the specified SSI module and places that data into the location specified by the ui32Data parameter. If there is no data in the FIFO, then this function returns a zero.

Note: Only the lower N bits of the value written to pui32Data contain valid data, where N is the data width as configured by SSIConfigSetExpClk(). For example, if the interface is configured for 8-bit data width, only the lower 8 bits of the value written to pui32Data contain valid data.

Parameters

ui32Base	specifies the SSI module base address.
pui32Data	is a pointer to a storage location for data that was received over the SSI interface.

Returns: Returns the number of elements read from the SSI receive FIFO.

Gets a data element from the SSI receive FIFO

Parameters

ui32Base	specifies the SSI module base address.
pui32Data	is a pointer to a storage location for data that was received over the SSI interface.

This function gets received data from the receive FIFO of the specified SSI module and places that data into the location specified by the ui32Data parameter. If there is no data in the FIFO, then this function returns a zero.

Note: Only the lower N bits of the value written to pui32Data contain valid data, where N is the data width as configured by

See also: SSIConfigSetExpClk(). For example, if the interface is configured for 8-bit data width, only the lower 8 bits of the value written to pui32Data contain valid data.

Returns: Returns the number of elements read from the SSI receive FIFO.

Definition at line 234 of file ssi.c.

void SSIDataPut	(	uint32_t	ui32Base,
		uint32_t	ui32Data
	)

Puts a data element into the SSI transmit FIFO.

This function places the supplied data into the transmit FIFO of the specified SSI module.

Note: The upper 32 - N bits of the ui32Data are discarded by the hardware, where N is the data width as configured by SSIConfigSetExpClk(). For example, if the interface is configured for 8-bit data width, the upper 24 bits of ui32Data are discarded.

Parameters

ui32Base	specifies the SSI module base address.
ui32Data	is the data to be transmitted over the SSI interface.

Returns: None

Definition at line 163 of file ssi.c.

int32_t SSIDataPutNonBlocking	(	uint32_t	ui32Base,
		uint32_t	ui32Data
	)

Puts a data element into the SSI transmit FIFO.

This function places the supplied data into the transmit FIFO of the specified SSI module. If there is no space in the FIFO, then this function returns a zero.

Note: The upper 32 - N bits of the ui32Data are discarded by the hardware, where N is the data width as configured by SSIConfigSetExpClk(). For example, if the interface is configured for 8-bit data width, the upper 24 bits of ui32Data are discarded.

Parameters

ui32Base	specifies the SSI module base address.
ui32Data	is the data to be transmitted over the SSI interface.

Returns: Returns the number of elements written to the SSI transmit FIFO.

Definition at line 133 of file ssi.c.

static void SSIDisable ( uint32_t ui32Base )

inlinestatic

Disables the synchronous serial port.

This function disables operation of the synchronous serial port.

Parameters

ui32Base specifies the SSI module base address.

Returns: None

Definition at line 267 of file ssi.h.

static void SSIDMADisable	(	uint32_t	ui32Base,
		uint32_t	ui32DMAFlags
	)

inlinestatic

Disable SSI DMA operation.

This function is used to disable SSI DMA features that were enabled by SSIDMAEnable(). The specified SSI DMA features are disabled.

Parameters

ui32Base	is the base address of the SSI port.
ui32DMAFlags	is a bit mask of the DMA features to disable. The parameter is the bitwise OR of any of the following values: SSI_DMA_RX : Disable DMA for receive. SSI_DMA_TX : Disable DMA for transmit.

Returns: None

Definition at line 669 of file ssi.h.

static void SSIDMAEnable	(	uint32_t	ui32Base,
		uint32_t	ui32DMAFlags
	)

inlinestatic

Enable SSI DMA operation.

The specified SSI DMA features are enabled. The SSI can be configured to use DMA for transmit and/or receive data transfers.

Note: The uDMA controller must also be set up before DMA can be used with the SSI.

Parameters

ui32Base	is the base address of the SSI port.
ui32DMAFlags	is a bit mask of the DMA features to enable. The parameter is the bitwise OR of any of the following values: SSI_DMA_RX : Enable DMA for receive. SSI_DMA_TX : Enable DMA for transmit.

Returns: None

Definition at line 639 of file ssi.h.

static void SSIEnable ( uint32_t ui32Base )

inlinestatic

Enables the synchronous serial port.

This function enables operation of the synchronous serial port. The synchronous serial port must be configured before it is enabled.

Parameters

ui32Base specifies the SSI module base address.

Returns: None

Definition at line 242 of file ssi.h.

static void SSIIntClear	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

inlinestatic

Clears SSI interrupt sources.

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

Note

Due to write buffers and synchronizers in the system it may take several clock cycles from a register write clearing an event in a module and until the event is actually cleared in the NVIC of the system CPU. It is recommended to clear the event source early in the interrupt service routine (ISR) to allow the event clear to propagate to the NVIC before returning from the ISR. At the same time, an early event clear allows new events of the same type to be pended instead of ignored if the event is cleared later in the ISR. It is the responsibility of the programmer to make sure that enough time has passed before returning from the ISR to avoid false re-triggering of the cleared event. A simple, although not necessarily optimal, way of clearing an event before returning from the ISR is:

Write to clear event (interrupt source). (buffered write)
Dummy read from the event source module. (making sure the write has propagated)
Wait two system CPU clock cycles (user code or two NOPs). (allowing cleared event to propagate through any synchronizers)

Parameters

ui32Base	specifies the SSI module base address.
ui32IntFlags	is a bit mask of the interrupt sources to be cleared. The parameter can consist of either or both of: SSI_RXTO : Timeout interrupt. SSI_RXOR : Overrun interrupt.

Returns: None

Definition at line 564 of file ssi.h.

static void SSIIntDisable	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

inlinestatic

Disables individual SSI interrupt sources.

Disables the indicated SSI interrupt sources.

Parameters

ui32Base	specifies the SSI module base address.
ui32IntFlags	is a bit mask of the interrupt sources to be disabled. SSI_TXFF SSI_RXFF SSI_RXTO SSI_RXOR

Returns: None

Definition at line 518 of file ssi.h.

static void SSIIntEnable	(	uint32_t	ui32Base,
		uint32_t	ui32IntFlags
	)

inlinestatic

Enables individual SSI interrupt sources.

Enables the indicated SSI interrupt sources. Only the sources that are enabled can be reflected to the processor interrupt; disabled sources have no effect on the processor.

Parameters

ui32Base	specifies the SSI module base address.
ui32IntFlags	is a bit mask of the interrupt sources to be enabled. SSI_TXFF SSI_RXFF SSI_RXTO SSI_RXOR

Returns: None

Definition at line 488 of file ssi.h.

void SSIIntRegister	(	uint32_t	ui32Base,
		void(*)(void)	pfnHandler
	)

Registers an interrupt handler for the synchronous serial port.

This sets the handler to be called when an SSI interrupt occurs. This will enable the global interrupt in the interrupt controller; specific SSI interrupts must be enabled via SSIIntEnable(). If necessary, it is the interrupt handler's responsibility to clear the interrupt source via SSIIntClear().

Parameters

ui32Base	specifies the SSI module base address.
pfnHandler	is a pointer to the function to be called when the synchronous serial port interrupt occurs.

Returns: None

See also: IntRegister() for important information about registering interrupt handlers.

Registers an interrupt handler for the synchronous serial port

Parameters

ui32Base	specifies the SSI module base address.
pfnHandler	is a pointer to the function to be called when the synchronous serial port interrupt occurs.

This sets the handler to be called when an SSI interrupt occurs. This will enable the global interrupt in the interrupt controller; specific SSI interrupts must be enabled via SSIIntEnable(). If necessary, it is the interrupt handler's responsibility to clear the interrupt source via SSIIntClear().

See also: IntRegister() for important information about registering interrupt handlers.

Returns: None

Definition at line 276 of file ssi.c.

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static uint32_t SSIIntStatus	(	uint32_t	ui32Base,
		bool	bMasked
	)

inlinestatic

Gets the current interrupt status.

This function returns the interrupt status for the SSI module. Either the raw interrupt status or the status of interrupts that are allowed to reflect to the processor can be returned.

Parameters

ui32Base	specifies the SSI module base address.
bMasked	selects either raw or masked interrupt. `false` : Raw interrupt status is required. `true` : Masked interrupt status is required.

Returns

Returns the current interrupt status as an OR'ed combination of:

Definition at line 598 of file ssi.h.

void SSIIntUnregister ( uint32_t ui32Base )

Unregisters an interrupt handler for the synchronous serial port.

This function will clear the handler to be called when a SSI interrupt occurs. This will also mask off the interrupt in the interrupt controller so that the interrupt handler no longer is called.

Parameters

ui32Base specifies the SSI module base address.

Returns: None

See also: IntRegister() for important information about registering interrupt handlers.

Unregisters an interrupt handler for the synchronous serial port

Parameters

ui32Base specifies the SSI module base address.

This function will clear the handler to be called when a SSI interrupt occurs. This will also mask 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

Definition at line 318 of file ssi.c.

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static uint32_t SSIStatus ( uint32_t ui32Base )

inlinestatic

Get the status of the SSI data buffers.

This function is used to poll the status of the internal FIFOs in the SSI module. The status of both TX and RX FIFO is returned.

Parameters

ui32Base specifies the SSI module base address.

Returns

Returns the current status of the internal SSI data buffers. The status is a bitwise OR'ed combination of:

SSI_RX_FULL : Receive FIFO full.
SSI_RX_NOT_EMPTY : Receive FIFO not empty.
SSI_TX_NOT_FULL : Transmit FIFO not full.
SSI_TX_EMPTY : Transmit FIFO empty.

Definition at line 416 of file ssi.h.

Macro Definition Documentation

#define SSI_DMA_RX 0x00000001

Definition at line 138 of file ssi.h.

#define SSI_DMA_TX 0x00000002

Definition at line 137 of file ssi.h.

#define SSI_FRF_MOTO_MODE_0 0x00000000

Definition at line 121 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_FRF_MOTO_MODE_1 0x00000002

Definition at line 122 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_FRF_MOTO_MODE_2 0x00000001

Definition at line 123 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_FRF_MOTO_MODE_3 0x00000003

Definition at line 124 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_FRF_NMW 0x00000020

Definition at line 126 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_FRF_TI 0x00000010

Definition at line 125 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_MODE_MASTER 0x00000000

Definition at line 128 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_MODE_SLAVE 0x00000001

Definition at line 129 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_MODE_SLAVE_OD 0x00000002

Definition at line 130 of file ssi.h.

Referenced by SSIConfigSetExpClk().

#define SSI_RX_FULL 0x00000008

Definition at line 110 of file ssi.h.

#define SSI_RX_NOT_EMPTY 0x00000004

Definition at line 111 of file ssi.h.

#define SSI_RXFF 0x00000004

Definition at line 101 of file ssi.h.

#define SSI_RXOR 0x00000001

Definition at line 103 of file ssi.h.

#define SSI_RXTO 0x00000002

Definition at line 102 of file ssi.h.

#define SSI_STATUS_MASK 0x0000000F

Definition at line 114 of file ssi.h.

Referenced by SSIStatus().

#define SSI_TX_EMPTY 0x00000001

Definition at line 113 of file ssi.h.

#define SSI_TX_NOT_FULL 0x00000002

Definition at line 112 of file ssi.h.

#define SSI_TXFF 0x00000008

Definition at line 100 of file ssi.h.

Functions

Detailed Description

Function Documentation

Macro Definition Documentation