Inter-Integrated Sound (I2S)

Data Structures
struct	mxc_i2s_config_t

Enumerations
enum	mxc_i2s_direction_t

Functions
int	MXC_I2S_Init (const mxc_i2s_config_t *config, void(*dma_ctz_cb)(int, int))
int	MXC_I2S_Shutdown (void)
int	MXC_I2S_Mute (void)
int	MXC_I2S_Unmute (void)
int	MXC_I2S_Pause (void)
int	MXC_I2S_Unpause (void)
int	MXC_I2S_Stop (void)
int	MXC_I2S_Start (void)
int	MXC_I2S_DMA_ClearFlags (void)
int	MXC_I2S_DMA_SetAddrCnt (void *src_addr, void *dst_addr, unsigned int count)
int	MXC_I2S_DMA_SetReload (void *src_addr, void *dst_addr, unsigned int count)

Detailed Description

---

Data Structure Documentation

mxc_i2s_config_t

struct mxc_i2s_config_t

I2S Configuration Struct.

Function Documentation

MXC_I2S_DMA_ClearFlags()

int MXC_I2S_DMA_ClearFlags

(

void

)

Clears DMA Interrupt Flags.

Clears the DMA Interrupt flags, should be called at the end of a dma_ctz_cb

Returns

E_NO_ERROR

MXC_I2S_DMA_SetAddrCnt()

int MXC_I2S_DMA_SetAddrCnt	(	void *	src_addr,
		void *	dst_addr,
		unsigned int	count
	)

Set DMA Addr (Source or Dest) and bytes to transfer.

Parameters

src_addr	The address to read data from (Audio Out)
dst_addr	The address to write data to (Audio In)
count	The length of the transfer in bytes

Sets the address to read/write data in memory and the length of the transfer. The unused addr parameter is ignored.

Returns

E_NO_ERROR

MXC_I2S_DMA_SetReload()

int MXC_I2S_DMA_SetReload	(	void *	src_addr,
		void *	dst_addr,
		unsigned int	count
	)

Sets the DMA reload address and count.

Parameters

src_addr	The address to read data from (Audio Out)
dst_addr	The address to write data to (Audio In)
count	The length of the transfer in bytes

If DMA reload is enabled, when the DMA has transfered $count bytes (a CTZ event occurs) the src, dst, and count registers will be set to these. The DMA reload flag clears after a reload occurs.

Returns

E_NO_ERROR

MXC_I2S_Init()

int MXC_I2S_Init	(	const mxc_i2s_config_t *	config,
		void(*)(int, int)	dma_ctz_cb
	)

Initialize I2S resources.

Parameters

config	see mxc_i2s_config_t I2S Config Struct
dma_ctz_cb	Function pointer to Count-to-Zero callback function.

Returns

Success/Fail, see Error Codes for a list of return codes.

MXC_I2S_Mute()

int MXC_I2S_Mute

(

void

)

Mute I2S Output.

Sets I2S data to zero, continues sending clock and accessing DMA

Returns

E_NO_ERROR

MXC_I2S_Pause()

int MXC_I2S_Pause

(

void

)

Pause I2S Output.

Similar to mute, but stops FIFO and DMA access, clocks continue

Returns

E_NO_ERROR

MXC_I2S_Shutdown()

int MXC_I2S_Shutdown

(

void

)

Release I2S.

De-configures the I2S protocol and stops DMA request

Returns

E_BAD_PARAM if DMA cannot be stopped, E_NO_ERROR otherwise

MXC_I2S_Start()

int MXC_I2S_Start

(

void

)

Starts I2S Output.

Starts I2S Output, automatically called by configure if requested

Returns

E_NO_ERROR

MXC_I2S_Stop()

int MXC_I2S_Stop

(

void

)

Stops I2S Output.

Similar to pause, but also halts clock

Returns

E_NO_ERROR

MXC_I2S_Unmute()

int MXC_I2S_Unmute

(

void

)

Unmute I2S Output.

Restores I2S data

Returns

E_NO_ERROR

MXC_I2S_Unpause()

int MXC_I2S_Unpause

(

void

)

Unpause I2S Output.

Similar to mute, but restarts FIFO and DMA access

Returns

E_NO_ERROR