XBARA: Inter-Peripheral Crossbar Switch

Overview

The MCUXpresso SDK provides a peripheral driver for the Inter-Peripheral Crossbar Switch (XBARA) block of MCUXpresso SDK devices.

The XBARA peripheral driver configures the XBARA (Inter-Peripheral Crossbar Switch) and handles initialization and configuration of the XBARA module.

XBARA driver has two parts:

• Signal connection interconnects input and output signals.
• Active edge feature - Some of the outputs provide an active edge detection. If an active edge occurs, an interrupt or a DMA request can be called. APIs handle user callbacks for the interrupts. The driver also includes API for clearing and reading status bits.

Function

XBARA Initialization

To initialize the XBARA driver, a state structure has to be passed into the initialization function. This block of memory keeps pointers to user's callback functions and parameters to these functions. The XBARA module is initialized by calling the XBARA_Init() function.

Call diagram

1. Call the "XBARA_Init()" function to initialize the XBARA module.
2. Optionally, call the "XBARA_SetSignalsConnection()" function to Set connection between the selected XBARA_IN[*] input and the XBARA_OUT[*] output signal. It connects the XBARA input to the selected XBARA output. A configuration structure of the "xbara_input_signal_t" type and "xbara_output_signal_t" type is required.
3. Call the "XBARA_SetOutputSignalConfig" function to set the active edge features, such interrupts or DMA requests. A configuration structure of the "xbara_control_config_t" type is required to point to structure that keeps configuration of control register.
4. Finally, the XBARA works properly.

Typical use case

Data Structures
struct	xbara_control_config_t
	Defines the configuration structure of the XBARA control register. More...

Enumerations
enum	xbara_active_edge_t {   kXBARA_EdgeNone = 0U,   kXBARA_EdgeRising = 1U,   kXBARA_EdgeFalling = 2U,   kXBARA_EdgeRisingAndFalling = 3U }
	XBARA active edge for detection. More...
enum	xbara_request_t {   kXBARA_RequestDisable = 0U,   kXBARA_RequestDMAEnable = 1U,   kXBARA_RequestInterruptEnalbe = 2U }
	Defines the XBARA DMA and interrupt configurations. More...
enum	xbara_status_flag_t {   kXBARA_EdgeDetectionOut0,   kXBARA_EdgeDetectionOut1,   kXBARA_EdgeDetectionOut2,   kXBARA_EdgeDetectionOut3 }
	XBARA status flags. More...

XBARA functional Operation.
void	XBARA_Init (XBARA_Type *base)
	Initializes the XBARA module. More...
void	XBARA_Deinit (XBARA_Type *base)
	Shuts down the XBARA module. More...
void	XBARA_SetSignalsConnection (XBARA_Type *base, xbar_input_signal_t input, xbar_output_signal_t output)
	Sets a connection between the selected XBARA_IN[*] input and the XBARA_OUT[*] output signal. More...
uint32_t	XBARA_GetStatusFlags (XBARA_Type *base)
	Gets the active edge detection status. More...
void	XBARA_ClearStatusFlags (XBARA_Type *base, uint32_t mask)
	Clears the edge detection status flags of relative mask. More...
void	XBARA_SetOutputSignalConfig (XBARA_Type *base, xbar_output_signal_t output, const xbara_control_config_t *controlConfig)
	Configures the XBARA control register. More...

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Data Structure Documentation

struct xbara_control_config_t

This structure keeps the configuration of XBARA control register for one output. Control registers are available only for a few outputs. Not every XBARA module has control registers.

Data Fields
xbara_active_edge_t	activeEdge
	Active edge to be detected. More...
xbara_request_t	requestType
	Selects DMA/Interrupt request. More...

Field Documentation

xbara_active_edge_t xbara_control_config_t::activeEdge

xbara_request_t xbara_control_config_t::requestType

Enumeration Type Documentation

enum xbara_active_edge_t

Enumerator
kXBARA_EdgeNone	Edge detection status bit never asserts.
kXBARA_EdgeRising	Edge detection status bit asserts on rising edges.
kXBARA_EdgeFalling	Edge detection status bit asserts on falling edges.
kXBARA_EdgeRisingAndFalling	Edge detection status bit asserts on rising and falling edges.

enum xbara_request_t

Enumerator
kXBARA_RequestDisable	Interrupt and DMA are disabled.
kXBARA_RequestDMAEnable	DMA enabled, interrupt disabled.
kXBARA_RequestInterruptEnalbe	Interrupt enabled, DMA disabled.

enum xbara_status_flag_t

This provides constants for the XBARA status flags for use in the XBARA functions.

Enumerator
kXBARA_EdgeDetectionOut0	XBAR_OUT0 active edge interrupt flag, sets when active edge detected.
kXBARA_EdgeDetectionOut1	XBAR_OUT1 active edge interrupt flag, sets when active edge detected.
kXBARA_EdgeDetectionOut2	XBAR_OUT2 active edge interrupt flag, sets when active edge detected.
kXBARA_EdgeDetectionOut3	XBAR_OUT3 active edge interrupt flag, sets when active edge detected.

Function Documentation

void XBARA_Init

(

XBARA_Type *

base

)

This function un-gates the XBARA clock.

Parameters

base	XBARA peripheral address.

void XBARA_Deinit

(

XBARA_Type *

base

)

This function disables XBARA clock.

Parameters

base	XBARA peripheral address.

void XBARA_SetSignalsConnection	(	XBARA_Type *	base,
		xbar_input_signal_t	input,
		xbar_output_signal_t	output
	)

This function connects the XBARA input to the selected XBARA output. If more than one XBARA module is available, only the inputs and outputs from the same module can be connected.

Example:

XBARA_SetSignalsConnection(XBARA, kXBARA_InputPIT_TRG0, kXBARA_OutputDMAMUX18);

Parameters

base	XBARA peripheral address.
input	XBARA input signal.
output	XBARA output signal.

uint32_t XBARA_GetStatusFlags

(

XBARA_Type *

base

)

This function gets the active edge detect status of all XBARA_OUTs. If the active edge occurs, the return value is asserted. When the interrupt or the DMA functionality is enabled for the XBARA_OUTx, this field is 1 when the interrupt or DMA request is asserted and 0 when the interrupt or DMA request has been cleared.

Parameters

base	XBARA peripheral address.

Returns

the mask of these status flag bits.

void XBARA_ClearStatusFlags	(	XBARA_Type *	base,
		uint32_t	mask
	)

Parameters

base	XBARA peripheral address.
mask	the status flags to clear.

void XBARA_SetOutputSignalConfig	(	XBARA_Type *	base,
		xbar_output_signal_t	output,
		const xbara_control_config_t *	controlConfig
	)

This function configures an XBARA control register. The active edge detection and the DMA/IRQ function on the corresponding XBARA output can be set.

Example:

xbara_control_config_t userConfig;
userConfig.activeEdge = kXBARA_EdgeRising;
userConfig.requestType = kXBARA_RequestInterruptEnalbe;
XBARA_SetOutputSignalConfig(XBARA, kXBARA_OutputDMAMUX18, &userConfig);

Parameters

base	XBARA peripheral address.
output	XBARA output number.
controlConfig	Pointer to structure that keeps configuration of control register.