eDisk.h File Reference

low-level SDC driver More...

Go to the source code of this file.

Macros
#define	_USE_WRITE   1
	set to 1 to enable disk write
#define	_USE_IOCTL   1
	set to 1 to enable ioctl()
#define	STA_NOINIT   0x01 /* Drive not initialized */
	Disk Status Bits (DSTATUS)
#define	STA_NODISK   0x02 /* No medium in the drive */
#define	STA_PROTECT   0x04 /* Write protected */
#define	CTRL_SYNC   0 /* Complete pending write process (needed at _FS_READONLY == 0) */
#define	GET_SECTOR_COUNT   1 /* Get media size (needed at _USE_MKFS == 1) */
#define	GET_SECTOR_SIZE   2 /* Get sector size (needed at _MAX_SS != _MIN_SS) */
#define	GET_BLOCK_SIZE   3 /* Get erase block size (needed at _USE_MKFS == 1) */
#define	CTRL_TRIM   4 /* Inform device that the data on the block of sectors is no longer used (needed at _USE_TRIM == 1) */
#define	CTRL_FORMAT   5 /* Create physical format on the media */
#define	CTRL_POWER_IDLE   6 /* Put the device idle state */
#define	CTRL_POWER_OFF   7 /* Put the device off state */
#define	CTRL_LOCK   8 /* Lock media removal */
#define	CTRL_UNLOCK   9 /* Unlock media removal */
#define	CTRL_EJECT   10 /* Eject media */
#define	MMC_GET_TYPE   50 /* Get card type */
#define	MMC_GET_CSD   51 /* Get CSD */
#define	MMC_GET_CID   52 /* Get CID */
#define	MMC_GET_OCR   53 /* Get OCR */
#define	MMC_GET_SDSTAT   54 /* Get SD status */
#define	ATA_GET_REV   60 /* Get F/W revision */
#define	ATA_GET_MODEL   61 /* Get model name */
#define	ATA_GET_SN   62 /* Get serial number */
#define	CT_MMC   0x01 /* MMC ver 3 */
#define	CT_SD1   0x02 /* SD ver 1 */
#define	CT_SD2   0x04 /* SD ver 2 */
#define	CT_SDC   (CT_SD1|CT_SD2) /* SD */
#define	CT_BLOCK   0x08 /* Block addressing */
#define	_DISKIO

Typedefs
typedef signed int	INT
typedef unsigned int	UINT
typedef signed char	CHAR
typedef unsigned char	UCHAR
typedef unsigned char	BYTE
typedef signed short	SHORT
typedef unsigned short	USHORT
typedef unsigned short	WORD
typedef signed long	LONG
typedef unsigned long	ULONG
typedef unsigned long	DWORD
typedef BYTE	DSTATUS
	Status of Disk Functions.

Enumerations
enum	BOOL { FALSE = 0 , TRUE }
	Boolean type.
enum	DRESULT {   RES_OK = 0 , RES_ERROR , RES_WRPRT , RES_NOTRDY ,   RES_PARERR }

Functions
DSTATUS	eDisk_Init (BYTE drive)
	Initialize the interface between microcontroller and the SD card. More...
DSTATUS	eDisk_Status (BYTE drive)
	Check the status of the SD card. More...
DRESULT	eDisk_Read (BYTE drv, BYTE *buff, DWORD sector, UINT count)
	Read bytes from SD card. More...
DRESULT	eDisk_ReadBlock (BYTE *buff, DWORD sector)
	Read 512-byte block from SD card. More...
DRESULT	eDisk_Write (BYTE drv, const BYTE *buff, DWORD sector, UINT count)
	Write bytes to SD card. More...
DRESULT	eDisk_WriteBlock (const BYTE *buff, DWORD sector)
	Write 512-byte block from SD card. More...
void	CS_Init (void)
	Configure SDC chip select. More...
void	disk_timerproc (void)
	This should be called every 10 ms. More...
DRESULT	disk_ioctl (BYTE drv, BYTE cmd, void *buff)
	Disk input/output. More...

Detailed Description

low-level SDC driver

This version of the driver has been configured to operate on the ST7735R, so that both the SDC card and the LCD use the same SSI port, but have different chip selects.

Version

V1.0

Author

Valvano

Copyright

Copyright 2026 by Jonathan W. Valvano, valva.nosp@m.no@m.nosp@m.ail.u.nosp@m.texa.nosp@m.s.edu,

Warning

AS-IS

Note

For more information see http://users.ece.utexas.edu/~valvano/

Date

December 29, 2026

Function Documentation

CS_Init()

void CS_Init

(

void

)

Configure SDC chip select.

Enable SDC chip select, so it is an output

Parameters

none

Returns

none

disk_ioctl()

DRESULT disk_ioctl	(	BYTE	drv,
		BYTE	cmd,
		void *	buff
	)

Disk input/output.

General purpose function for all disk I/O

Parameters

drv	(only drive 0 is supported)
cmd	disk command
buff	pointer to RAM input/output data

Returns

result (0 means OK)

disk_timerproc()

void disk_timerproc

(

void

)

This should be called every 10 ms.

This implements timeout functions

Parameters

none

Returns

none

eDisk_Init()

DSTATUS eDisk_Init

(

BYTE

drive

)

Initialize the interface between microcontroller and the SD card.

Turn on PLL. Since this program initializes the disk, it must run with the disk periodic task operating.

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
STA_NOINIT	0x01	Drive not initialized
STA_NODISK	0x02	No medium in the drive
STA_PROTECT	0x04	Write protected

Parameters

drive

number (only drive 0 is supported)

Returns

status (0 means OK)

eDisk_Read()

DRESULT eDisk_Read	(	BYTE	drv,
		BYTE *	buff,
		DWORD	sector,
		UINT	count
	)

Read bytes from SD card.

Read data from the SD card (write to RAM)

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
RES_ERROR	0x01	R/W Error
RES_WRPRT	0x02	Write Protected
RES_NOTRDY	0x03	Not Ready
RES_PARERR	0x04	Invalid Parameter

Parameters

drv	(only drive 0 is supported)
buff	pointer to an empty RAM buffer
sector	sector number of SD card to read: 0,1,2,...
count	number of sectors to read

Returns

result (0 means OK)

eDisk_ReadBlock()

DRESULT eDisk_ReadBlock	(	BYTE *	buff,
		DWORD	sector
	)

Read 512-byte block from SD card.

Read one block from the SD card (write to RAM)

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
RES_ERROR	0x01	R/W Error
RES_WRPRT	0x02	Write Protected
RES_NOTRDY	0x03	Not Ready
RES_PARERR	0x04	Invalid Parameter

Parameters

buff	pointer to an empty RAM buffer
sector	sector number of SD card to read: 0,1,2,...

Returns

result (0 means OK)

eDisk_Status()

DSTATUS eDisk_Status

(

BYTE

drive

)

Check the status of the SD card.

Checks the status of the secure digital care.

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
STA_NOINIT	0x01	Drive not initialized
STA_NODISK	0x02	No medium in the drive
STA_PROTECT	0x04	Write protected

Parameters

drive

number (only drive 0 is supported)

Returns

status (0 means OK)

eDisk_Write()

DRESULT eDisk_Write	(	BYTE	drv,
		const BYTE *	buff,
		DWORD	sector,
		UINT	count
	)

Write bytes to SD card.

write data to the SD card (read to RAM)

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
RES_ERROR	0x01	R/W Error
RES_WRPRT	0x02	Write Protected
RES_NOTRDY	0x03	Not Ready
RES_PARERR	0x04	Invalid Parameter

Parameters

drv	(only drive 0 is supported)
buff	pointer to RAM buffer with data
sector	sector number of SD card to write: 0,1,2,...
count	number of sectors to write

Returns

result (0 means OK)

eDisk_WriteBlock()

DRESULT eDisk_WriteBlock	(	const BYTE *	buff,
		DWORD	sector
	)

Write 512-byte block from SD card.

Write one block to the SD card (read to RAM)

Return parameter

Return	Value	Meaning
RES_OK	0x00	Successful
RES_ERROR	0x01	R/W Error
RES_WRPRT	0x02	Write Protected
RES_NOTRDY	0x03	Not Ready
RES_PARERR	0x04	Invalid Parameter

Parameters

buff	pointer to RAM buffer with 512 bytes of data
sector	sector number of SD card to write: 0,1,2,...

Returns

result (0 means OK)