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| #include <avr/io.h> |
| #include <util/delay.h> |
| #include "fat16.h" |
| #include "sdc.h" |
| #include "ssc.h" |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Module name: mmc.c |
| // Compiler used: avr-gcc 3.4.5 |
| // Last Modifikation: 24.07.2007 |
| // Version: 1.05 |
| // Authors: Stephan Busker |
| // Description: Source files for connecting to an sdcard using the SSC |
| // |
| //........................................................................................................................................ |
| // Functions: u8 SDC_init(void); |
| // u8 SDC_PutCommand (u8*CMD); |
| // u8 SDC_PutSector(u32 addr,u8*Buffer); |
| // u8 SDC_GetSector(u32 addr,u8*Buffer); |
| // void SDC_GetBlock(u8*CMD,u8*Buffer,u16 Bytes); |
| // |
| ////........................................................................................................................................ |
| // ext. functions: extern void SSC_Init(void); |
| // extern u8 SSC_GetChar (void); |
| // extern void SSC_PutChar (u8); |
| // extern void SSC_Enable(void); |
| // extern void SSC_Disable(void); |
| //........................................................................................................................................ |
| // |
| // URL: www.Mikro-Control.de |
| // mailto: stephan.busker@mikro-control.de |
| //________________________________________________________________________________________________________________________________________ |
| |
| |
| |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Funtion: SDC_Init(void); |
| // |
| // Description: This function initialises the SDCard to spi-mode. |
| // |
| // |
| // Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode. |
| //________________________________________________________________________________________________________________________________________ |
| |
| u8 SDC_Init(void) |
| { |
| u8 Timeout = 0; |
| u8 CMD[] = {0x40,0x00,0x00,0x00,0x00,0x95}; |
| u16 a = 0; |
| u8 b = 0; |
| |
| SSC_Init(); // Initialise SSC to transmit data to the sdcard. |
| |
| |
| _delay_ms(10); // before initialising the sdcard wait for 10ms |
| |
| |
| for (b=0;b<0x0f;b++) // sending 74Clocks brings the sdcard into spimode. |
| { |
| _delay_us(1); // wait at least 1us between the characters. |
| SSC_PutChar(0xff); |
| } |
| |
| |
| while(SDC_PutCommand (CMD) !=1) // Sending CMD0 (Reset) to the sdcard. |
| { |
| if (Timeout++ > 200) |
| { |
| return(1); |
| } |
| } |
| |
| Timeout = 0; |
| CMD[0] = 0x41; |
| CMD[5] = 0xFF; |
| while( SDC_PutCommand (CMD) !=0) // Sending CMD1 to the sdcard. |
| { |
| if (Timeout++ > 100) |
| { |
| return(2); |
| } |
| } |
| |
| SSC_Disable(); // disable sdcard. |
| return(0); |
| } |
| |
| |
| |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Funtion: SDC_PutCommand(* CMD); |
| // |
| // Description: This function initialises the SDCard to spi-mode. |
| // |
| // |
| // Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode. |
| //________________________________________________________________________________________________________________________________________ |
| |
| u8 SDC_PutCommand (u8*CMD) |
| { |
| u8 tmp = 0xff; |
| u8 Timeout = 0; |
| u16 a = 0; |
| |
| |
| #ifdef SSC_RX_FIFO |
| SSC_ClearRxFifo(); |
| #endif |
| SSC_Disable(); // disable chipselect |
| SSC_PutChar(0xFF); // Send 8 Clocks to the sdcard while card is not selected. |
| SSC_Enable(); // enable chipselect. |
| |
| if (*CMD == 0x41) _delay_ms(10); // if command is CMD0 generate a short delay. |
| |
| for (a = 0;a<0x06;a++) // send the command sequence to the sdcard (6 bytes) |
| { |
| SSC_PutChar(*CMD++); |
| } |
| |
| #ifdef SSC_RX_FIFO |
| SSC_ClearRxFifo(); |
| #endif |
| while (tmp == 0xff) // Wait for response from sdcard. |
| { |
| tmp = SSC_GetChar(); |
| if (Timeout++ > 100) |
| { |
| break; // or timeout. |
| } |
| } |
| |
| return(tmp); |
| } |
| |
| |
| |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Funtion: SDC_PutSector(void); |
| // |
| // Description: This function writes one sector of data to the SSC |
| // |
| // |
| // Returnvalue: none |
| //________________________________________________________________________________________________________________________________________ |
| |
| u8 SDC_PutSector(u32 addr,u8*Buffer) |
| { |
| u8 tmp; |
| u8 CMD[] = {0x58,0x00,0x00,0x00,0x00,0xFF}; |
| |
| addr = addr << 9; // convert sectoradress to byteadress |
| |
| CMD[1] = ((addr & 0xFF000000) >>24 ); |
| CMD[2] = ((addr & 0x00FF0000) >>16 ); |
| CMD[3] = ((addr & 0x0000FF00) >>8 ); |
| |
| tmp = SDC_PutCommand (CMD); // send command to sdcard. |
| if (tmp != 0) |
| { |
| return(tmp); |
| } |
| |
| #ifdef SSC_RX_FIFO |
| SSC_ClearRxFifo(); |
| #endif |
| for (u8 a=0;a<100;a++) // wait until sdcard is ready |
| { |
| SSC_GetChar(); |
| } |
| |
| SSC_PutChar(0xFE); // send start of header to the SSC |
| |
| for (u16 a=0;a<512;a++) // transmitt one sector (normaly 512bytes) of data to the sdcard. |
| { |
| SSC_PutChar(*Buffer++); |
| } |
| |
| SSC_PutChar(0xFF); // write two bytes of crc to the sdcard (not used in spi-mode) |
| SSC_PutChar(0xFF); |
| #ifdef SSC_RX_FIFO |
| SSC_ClearRxFifo(); |
| #endif |
| |
| while (SSC_GetChar() != 0xff){}; // wait untile the sdcard is ready. |
| |
| SSC_Disable(); // disable sdcard. |
| |
| return(0); |
| } |
| |
| |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Funtion: SDC_GetSector(u32 addr,u8*Buffer); |
| // |
| // Description: This function reads one sector of data from the SSC |
| // |
| // |
| // Returnvalue: none |
| //________________________________________________________________________________________________________________________________________ |
| |
| u8 SDC_GetSector(u32 addr,u8*Buffer) |
| { |
| u8 CMD[] = {0x51,0x00,0x00,0x00,0x00,0xFF}; |
| |
| addr = addr << 9; // convert sectoradress to byteadress. |
| |
| CMD[1] = ((addr & 0xFF000000) >>24 ); |
| CMD[2] = ((addr & 0x00FF0000) >>16 ); |
| CMD[3] = ((addr & 0x0000FF00) >>8 ); |
| |
| SDC_GetBlock(CMD,Buffer,512); // read specified sector from sdcard. |
| |
| return(0); |
| } |
| |
| |
| |
| //________________________________________________________________________________________________________________________________________ |
| // Funtion: SDC_GetBlock(void); |
| // |
| // Description: This function reads one block of data of s16 bytes from the SSC. |
| // |
| // |
| // Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode. |
| //________________________________________________________________________________________________________________________________________ |
| |
| void SDC_GetBlock(u8*CMD,u8*Buffer,u16 Bytes) |
| { |
| if (SDC_PutCommand (CMD) != 0) // Send command to the sdcard. |
| { |
| return; |
| } |
| |
| #ifdef SSC_RX_FIFO |
| SSC_ClearRxFifo(); |
| #endif |
| while (SSC_GetChar() != 0xfe){}; // wait until the sdcard is ready to transmitt data. |
| |
| for (u16 a=0;a<Bytes;a++) // read the block from the SSC (normaly 512Bytes) |
| { |
| *Buffer++ = SSC_GetChar(); |
| } |
| |
| SSC_GetChar(); // Read two bytes CRC- checksum (not used in spi-mode) |
| SSC_GetChar(); |
| SSC_Disable(); // disable sdcard. |
| } |
| |
| |
| |