Mikroelektronika MIKROE-724 データシート

394

mikoBasic PRO for dsPIC30/33 and PIC24

MikroElektronika

Mmc_Fat_Init

Prototype

sub function Mmc_Fat_Init() as word

Description Initializes MMC/SD card, reads MMC/SD FAT16 boot sector and extracts necessary data needed by

the library.

Parameters None.
Returns

- if MMC/SD card was detected and successfully initialized

- if FAT16 boot sector was not found

255

- if MMC/SD card was not detected

Requires

Global variables:

Mmc_Chip_Select

: Chip Select line

Mmc_Chip_Select_Direction

: Direction of the Chip Select pin

must be defined before using this function.

The appropriate hardware SPI module must be previously initialized. See the SPIx_Init, SPIx_Init_

Advanced routines.

Example

‘ MMC module connections

dim Mmc_Chip_Select as sbit sfr at LATF0_bit

dim Mmc_Chip_Select_Direction as sbit sfr at TRISF0_bit

‘ MMC module connections

...

‘ Initialize the SPI module

SPI1_Init_Advanced(_SPI_MASTER, _SPI_8_BIT, _SPI_PRESCALE_SEC_1, _SPI_

PRESCALE_PRI_64,_SPI_SS_DISABLE, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_

HIGH, _SPI_ACTIVE_2_IDLE)

‘ Initialize MMC/SD card and MMC_FAT16 library globals

Mmc_Fat_Init()

‘ Reinitialize the SPI module at higher speed (change primary prescaler).

SPI1_Init_Advanced(_SPI_MASTER, _SPI_8_BIT, _SPI_PRESCALE_SEC_1, _SPI_

PRESCALE_PRI_4,_SPI_SS_DISABLE, _SPI_DATA_SAMPLE_MIDDLE, _SPI_CLK_IDLE_

HIGH, _SPI_ACTIVE_2_IDLE)

Notes

MMC/SD card has to be formatted to FAT16 file system.