This is Petit FAT File System Module for mbed NXP LPC1768. The ported library from http://elm-chan.org/fsw/ff/00index_p.html made by Mr. ChaN. The connection is same as SDCard library here http://mbed.org/projects/cookbook/wiki/SDCard . If you need change a pin, You can find the definition at libpff/connect.h :)
Diff: libpff/mmc.c
- Revision:
- 0:b5453be5ad07
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libpff/mmc.c Tue Jun 01 12:23:29 2010 +0000 @@ -0,0 +1,268 @@ +/*-----------------------------------------------------------------------*/ +/* PFF - Low level disk control module for ATtiny85 (C)ChaN, 2009 */ +/*-----------------------------------------------------------------------*/ + +#define _WRITE_FUNC 1 + +#include "diskio.h" +#include "mbed.h" +#include "connect.h" + +/* Definitions for MMC/SDC command */ +#define CMD0 (0x40+0) /* GO_IDLE_STATE */ +#define CMD1 (0x40+1) /* SEND_OP_COND (MMC) */ +#define ACMD41 (0xC0+41) /* SEND_OP_COND (SDC) */ +#define CMD8 (0x40+8) /* SEND_IF_COND */ +#define CMD16 (0x40+16) /* SET_BLOCKLEN */ +#define CMD17 (0x40+17) /* READ_SINGLE_BLOCK */ +#define CMD24 (0x40+24) /* WRITE_BLOCK */ +#define CMD55 (0x40+55) /* APP_CMD */ +#define CMD58 (0x40+58) /* READ_OCR */ + +SPI device(CONNECT_MOSI,CONNECT_MISO,CONNECT_SCK); +DigitalOut cs(CONNECT_CS); + +/* Port Controls (Platform dependent) */ +#define SELECT() cs.write(0) /* MMC CS = L */ +#define DESELECT() cs.write(1) /* MMC CS = H */ +#define MMC_SEL !cs.read() /* MMC CS status (true:selected) */ + +void xmit_spi (BYTE c) { + device.write(c); /* Send a byte */ +} + +BYTE rcv_spi (void) { + return device.write(0xff); +} + +/*-------------------------------------------------------------------------- + + Module Private Functions + +---------------------------------------------------------------------------*/ + +static +BYTE CardType; + + +/*-----------------------------------------------------------------------*/ +/* Deselect the card and release SPI bus */ +/*-----------------------------------------------------------------------*/ + +static +void release_spi (void) { + DESELECT(); + rcv_spi(); +} + + +/*-----------------------------------------------------------------------*/ +/* Send a command packet to MMC */ +/*-----------------------------------------------------------------------*/ + +static +BYTE send_cmd ( + BYTE cmd, /* Command byte */ + DWORD arg /* Argument */ +) { + BYTE n, res; + + + if (cmd & 0x80) { /* ACMD<n> is the command sequense of CMD55-CMD<n> */ + cmd &= 0x7F; + res = send_cmd(CMD55, 0); + if (res > 1) return res; + } + + /* Select the card */ + DESELECT(); + rcv_spi(); + SELECT(); + rcv_spi(); + + /* Send a command packet */ + xmit_spi(cmd); /* Start + Command index */ + xmit_spi((BYTE)(arg >> 24)); /* Argument[31..24] */ + xmit_spi((BYTE)(arg >> 16)); /* Argument[23..16] */ + xmit_spi((BYTE)(arg >> 8)); /* Argument[15..8] */ + xmit_spi((BYTE)arg); /* Argument[7..0] */ + n = 0x01; /* Dummy CRC + Stop */ + if (cmd == CMD0) n = 0x95; /* Valid CRC for CMD0(0) */ + if (cmd == CMD8) n = 0x87; /* Valid CRC for CMD8(0x1AA) */ + xmit_spi(n); + + /* Receive a command response */ + n = 10; /* Wait for a valid response in timeout of 10 attempts */ + do { + res = rcv_spi(); + } while ((res & 0x80) && --n); + + return res; /* Return with the response value */ +} + + + +/*-------------------------------------------------------------------------- + + Public Functions + +---------------------------------------------------------------------------*/ + + +/*-----------------------------------------------------------------------*/ +/* Initialize Disk Drive */ +/*-----------------------------------------------------------------------*/ + +DSTATUS disk_initialize (void) { + BYTE n, cmd, ty, ocr[4]; + WORD tmr; + + DESELECT(); + device.format(8); + device.frequency(SPI_FREQ); + +#if _WRITE_FUNC + if (MMC_SEL) disk_writep(0, 0); /* Finalize write process if it is in progress */ +#endif + for (n = 100; n; n--) rcv_spi(); /* Dummy clocks */ + + ty = 0; + if (send_cmd(CMD0, 0) == 1) { /* Enter Idle state */ + if (send_cmd(CMD8, 0x1AA) == 1) { /* SDv2 */ + for (n = 0; n < 4; n++) ocr[n] = rcv_spi(); /* Get trailing return value of R7 resp */ + if (ocr[2] == 0x01 && ocr[3] == 0xAA) { /* The card can work at vdd range of 2.7-3.6V */ + for (tmr = 12000; tmr && send_cmd(ACMD41, 1UL << 30); tmr--) ; /* Wait for leaving idle state (ACMD41 with HCS bit) */ + if (tmr && send_cmd(CMD58, 0) == 0) { /* Check CCS bit in the OCR */ + for (n = 0; n < 4; n++) ocr[n] = rcv_spi(); + ty = (ocr[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2; /* SDv2 (HC or SC) */ + } + } + } else { /* SDv1 or MMCv3 */ + if (send_cmd(ACMD41, 0) <= 1) { + ty = CT_SD1; + cmd = ACMD41; /* SDv1 */ + } else { + ty = CT_MMC; + cmd = CMD1; /* MMCv3 */ + } + for (tmr = 25000; tmr && send_cmd(cmd, 0); tmr--) ; /* Wait for leaving idle state */ + if (!tmr || send_cmd(CMD16, 512) != 0) /* Set R/W block length to 512 */ + ty = 0; + } + } + CardType = ty; + release_spi(); + + return ty ? 0 : STA_NOINIT; +} + + + +/*-----------------------------------------------------------------------*/ +/* Read partial sector */ +/*-----------------------------------------------------------------------*/ + +DRESULT disk_readp ( + BYTE *buff, /* Pointer to the read buffer (NULL:Read bytes are forwarded to the stream) */ + DWORD lba, /* Sector number (LBA) */ + WORD ofs, /* Byte offset to read from (0..511) */ + WORD cnt /* Number of bytes to read (ofs + cnt mus be <= 512) */ +) { + DRESULT res; + BYTE rc; + WORD bc; + + + if (!(CardType & CT_BLOCK)) lba *= 512; /* Convert to byte address if needed */ + + res = RES_ERROR; + if (send_cmd(CMD17, lba) == 0) { /* READ_SINGLE_BLOCK */ + + bc = 30000; + do { /* Wait for data packet in timeout of 100ms */ + rc = rcv_spi(); + } while (rc == 0xFF && --bc); + + if (rc == 0xFE) { /* A data packet arrived */ + bc = 514 - ofs - cnt; + + /* Skip leading bytes */ + if (ofs) { + do { + rcv_spi(); + } while (--ofs); + } + + /* Receive a part of the sector */ + if (buff) { /* Store data to the memory */ + do { + *buff++ = rcv_spi(); + } while (--cnt); + } else { /* Forward data to the outgoing stream (depends on the project) */ + do { + rcv_spi(); + } while (--cnt); + } + + /* Skip trailing bytes and CRC */ + do rcv_spi(); + while (--bc); + + res = RES_OK; + } + } + + release_spi(); + + return res; +} + + + +/*-----------------------------------------------------------------------*/ +/* Write partial sector */ +/*-----------------------------------------------------------------------*/ +#if _WRITE_FUNC + +DRESULT disk_writep ( + const BYTE *buff, /* Pointer to the bytes to be written (NULL:Initiate/Finalize sector write) */ + DWORD sa /* Number of bytes to send, Sector number (LBA) or zero */ +) { + DRESULT res; + WORD bc; + static WORD wc; + + + res = RES_ERROR; + + if (buff) { /* Send data bytes */ + bc = (WORD)sa; + while (bc && wc) { /* Send data bytes to the card */ + xmit_spi(*buff++); + wc--; + bc--; + } + res = RES_OK; + } else { + if (sa) { /* Initiate sector write process */ + if (!(CardType & CT_BLOCK)) sa *= 512; /* Convert to byte address if needed */ + if (send_cmd(CMD24, sa) == 0) { /* WRITE_SINGLE_BLOCK */ + xmit_spi(0xFF); + xmit_spi(0xFE); /* Data block header */ + wc = 512; /* Set byte counter */ + res = RES_OK; + } + } else { /* Finalize sector write process */ + bc = wc + 2; + while (bc--) xmit_spi(0); /* Fill left bytes and CRC with zeros */ + if ((rcv_spi() & 0x1F) == 0x05) { /* Receive data resp and wait for end of write process in timeout of 300ms */ + for (bc = 65000; rcv_spi() != 0xFF && bc; bc--) ; /* Wait ready */ + if (bc) res = RES_OK; + } + release_spi(); + } + } + + return res; +} +#endif