Secure Digital High Capacity(SDHC)

Modules
	SDHC_Registers

Data Structures
struct	mxc_sdhc_cfg_t
struct	mxc_sdhc_cmd_cfg_t

Typedefs
typedef void(*	mxc_sdhc_callback_fn) (int error_code)

Functions
int	MXC_SDHC_Init (const mxc_sdhc_cfg_t *cfg)
void	MXC_SDHC_PowerUp (void)
void	MXC_SDHC_PowerDown (void)
int	MXC_SDHC_Shutdown (void)
void	MXC_SDHC_Set_Clock_Config (unsigned int clk_div)
unsigned int	MXC_SDHC_Get_Clock_Config (void)
unsigned int	MXC_SDHC_Get_Input_Clock_Freq (void)
int	MXC_SDHC_SendCommand (mxc_sdhc_cmd_cfg_t *sd_cmd_cfg)
int	MXC_SDHC_SendCommandAsync (mxc_sdhc_cmd_cfg_t *sd_cmd_cfg)
void	MXC_SDHC_Handler (void)
int	MXC_SDHC_Card_Inserted (void)
void	MXC_SDHC_ClearFlags (uint32_t mask)
unsigned	MXC_SDHC_GetFlags (void)
void	MXC_SDHC_Reset (void)
void	MXC_SDHC_Reset_CMD_DAT (void)
int	MXC_SDHC_Card_Busy (void)
unsigned int	MXC_SDHC_Get_Host_Cn_1 (void)
uint32_t	MXC_SDHC_Get_Response32 (void)
uint32_t	MXC_SDHC_Get_Response32_Auto (void)
void	MXC_SDHC_Get_Response128 (unsigned char *response)

Detailed Description

---

Data Structure Documentation

mxc_sdhc_cfg_t

struct mxc_sdhc_cfg_t

Used to configure voltage and clock for sdhc interface.

Data Fields
unsigned int	bus_voltage
unsigned int	block_gap
unsigned int	clk_div

Field Documentation

block_gap

unsigned int block_gap

Set block gap register default is 0

bus_voltage

unsigned int bus_voltage

Use constants above for 1.8V, 3.0V, 3.3V.

clk_div

unsigned int clk_div

Divider for SD clock

mxc_sdhc_cmd_cfg_t

struct mxc_sdhc_cmd_cfg_t

Used to configure sdhc interface.

Data Fields
uint32_t	sdma
uint32_t	block_size
uint32_t	block_count
uint32_t	arg_1
unsigned int	dma
unsigned int	direction
uint32_t	command
uint32_t	host_control_1
mxc_sdhc_callback_fn	callback

Field Documentation

arg_1

uint32_t arg_1

Argument 1 holds the arguments for the commands sent to the card

block_count

uint32_t block_count

Number of blocks to transfer

block_size

uint32_t block_size

Size of transfer block in bytes

callback

mxc_sdhc_callback_fn callback

Function pointer to completion callback function, NULL if not desired

command

uint32_t command

Command to be issued on bus (CMD0, CMD1, ...)

direction

unsigned int direction

Direction of transfer

dma

unsigned int dma

DMA enable bit

host_control_1

uint32_t host_control_1

Host control register 1 to be assigned before command is issued

sdma

uint32_t sdma

SDMA register for read or write transaction

Typedef Documentation

mxc_sdhc_callback_fn

typedef void(* mxc_sdhc_callback_fn) (int error_code)

Callback function type used in asynchromous SDHC communications requests.

The function declaration for the SDHC callback is:

void callback(int error_code);

error_code	An error code if the active transaction had a failure or E_NO_ERROR if successful.

Function Documentation

MXC_SDHC_Card_Busy()

int MXC_SDHC_Card_Busy

(

void

)

Check if Card is busy.

Returns

1 card busy , 0 card is not busy

MXC_SDHC_Card_Inserted()

int MXC_SDHC_Card_Inserted

(

void

)

See if card is inserted.

Returns

1 is card inserted, 0 is card not inserted

MXC_SDHC_ClearFlags()

void MXC_SDHC_ClearFlags

(

uint32_t

mask

)

Clear interrupt flags.

Parameters

mask	Mask of the SDHC interrupts to clear, see SDHC_INT_STAT Register.

MXC_SDHC_Get_Clock_Config()

unsigned int MXC_SDHC_Get_Clock_Config

(

void

)

Get clock divider.

Returns

Clock divider setting

MXC_SDHC_Get_Host_Cn_1()

unsigned int MXC_SDHC_Get_Host_Cn_1

(

void

)

Retrieve host control 1 register.

Returns

host control register

MXC_SDHC_Get_Input_Clock_Freq()

unsigned int MXC_SDHC_Get_Input_Clock_Freq

(

void

)

Get the input clock frequency for the SDHC peripheral.

Returns

Input clock frequency in Hz

MXC_SDHC_Get_Response128()

void MXC_SDHC_Get_Response128

(

unsigned char *

response

)

Read a 128-bit command response.

Parameters

response

Pointer to storage for response (16 bytes)

This function may be used to read response type R2 (CID or CSD)

MXC_SDHC_Get_Response32()

uint32_t MXC_SDHC_Get_Response32

(

void

)

Read a 32-bit command response.

This function may be used to read response types R1, R1a, R3, R4, R5, R5b, and R6

Returns

Command response

MXC_SDHC_Get_Response32_Auto()

uint32_t MXC_SDHC_Get_Response32_Auto

(

void

)

Read a 32-bit command response for Auto commands.

This function may be used to read response types R1b and R1 after an Auto CMD12 or Auto CMD23

Returns

Command response

MXC_SDHC_GetFlags()

unsigned MXC_SDHC_GetFlags

(

void

)

Get interrupt flags.

Returns

Mask of active flags.

MXC_SDHC_Handler()

void MXC_SDHC_Handler

(

void

)

SDHC interrupt handler.

This function should be called by the application from the interrupt handler if SDHC interrupts are enabled. Alternately, this function can be periodically called by the application if SDHC interrupts are disabled. Only necessary to call this when using asynchronous functions.

MXC_SDHC_Init()

int MXC_SDHC_Init

(

const mxc_sdhc_cfg_t *

cfg

)

Initialize and enable SDHC module.

Parameters

cfg	Pointer to SDHC configuration.

Returns

E_NO_ERROR SDHC initialized successfully, error if unsuccessful.

MXC_SDHC_SendCommand()

int MXC_SDHC_SendCommand

(

mxc_sdhc_cmd_cfg_t *

sd_cmd_cfg

)

Send Command, blocking.

Parameters

sd_cmd_cfg

The sd command configuration

Returns

E_NO_ERROR, error if unsuccessful.

MXC_SDHC_SendCommandAsync()

int MXC_SDHC_SendCommandAsync

(

mxc_sdhc_cmd_cfg_t *

sd_cmd_cfg

)

Send SDHC command Async.

Parameters

sd_cmd_cfg

The sd command configuration

Returns

E_NO_ERROR, error if unsuccessful.

MXC_SDHC_Set_Clock_Config()

void MXC_SDHC_Set_Clock_Config

(

unsigned int

clk_div

)

Set clock divider.

Parameters

clk_div

Divider setting

Returns

E_NO_ERROR upon success, error if unsuccessful.

MXC_SDHC_Shutdown()

int MXC_SDHC_Shutdown

(

void

)

Shutdown SDHC module.

Returns

E_NO_ERROR SDHC shutdown successfully, error if unsuccessful.