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Rev	Author	Line No.	Line
231	killagreg	1	#include <avr/io.h>
		2	#include <util/delay.h>
		3	#include "fat16.h"
		4	#include "sdc.h"
		5	#include "ssc.h"
		6
		7	//________________________________________________________________________________________________________________________________________
		8	// Module name: mmc.c
		9	// Compiler used: avr-gcc 3.4.5
		10	// Last Modifikation: 24.07.2007
		11	// Version: 1.05
		12	// Authors: Stephan Busker
		13	// Description: Source files for connecting to an sdcard using the SSC
		14	//
		15	//........................................................................................................................................
		16	// Functions: u8 SDC_init(void);
		17	// u8 SDC_PutCommand (u8*CMD);
		18	// u8 SDC_PutSector(u32 addr,u8*Buffer);
		19	// u8 SDC_GetSector(u32 addr,u8*Buffer);
		20	// void SDC_GetBlock(u8CMD,u8Buffer,u16 Bytes);
		21	//
		22	////........................................................................................................................................
		23	// ext. functions: extern void SSC_Init(void);
		24	// extern u8 SSC_GetChar (void);
		25	// extern void SSC_PutChar (u8);
		26	// extern void SSC_Enable(void);
		27	// extern void SSC_Disable(void);
		28	//........................................................................................................................................
		29	//
		30	// URL: www.Mikro-Control.de
		31	// mailto: stephan.busker@mikro-control.de
		32	//________________________________________________________________________________________________________________________________________
		33
		34
		35
		36
		37	//________________________________________________________________________________________________________________________________________
		38	// Funtion: SDC_Init(void);
		39	//
		40	// Description: This function initialises the SDCard to spi-mode.
		41	//
		42	//
		43	// Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode.
		44	//________________________________________________________________________________________________________________________________________
		45
		46	u8 SDC_Init(void)
		47	{
		48	u8 Timeout = 0;
		49	u8 CMD[] = {0x40,0x00,0x00,0x00,0x00,0x95};
		50	u16 a = 0;
		51	u8 b = 0;
		52
		53	SSC_Init(); // Initialise SSC to transmit data to the sdcard.
		54
		55
		56	_delay_ms(10); // before initialising the sdcard wait for 10ms
		57
		58
		59	for (b=0;b<0x0f;b++) // sending 74Clocks brings the sdcard into spimode.
		60	{
		61	_delay_us(1); // wait at least 1us between the characters.
		62	SSC_PutChar(0xff);
		63	}
		64
		65
		66	while(SDC_PutCommand (CMD) !=1) // Sending CMD0 (Reset) to the sdcard.
		67	{
		68	if (Timeout++ > 200)
		69	{
		70	return(1);
		71	}
		72	}
		73
		74	Timeout = 0;
		75	CMD[0] = 0x41;
		76	CMD[5] = 0xFF;
		77	while( SDC_PutCommand (CMD) !=0) // Sending CMD1 to the sdcard.
		78	{
		79	if (Timeout++ > 100)
		80	{
		81	return(2);
		82	}
		83	}
		84
		85	SSC_Disable(); // disable sdcard.
		86	return(0);
		87	}
		88
		89
		90
		91
		92	//________________________________________________________________________________________________________________________________________
		93	// Funtion: SDC_PutCommand(* CMD);
		94	//
		95	// Description: This function initialises the SDCard to spi-mode.
		96	//
		97	//
		98	// Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode.
		99	//________________________________________________________________________________________________________________________________________
		100
		101	u8 SDC_PutCommand (u8*CMD)
		102	{
		103	u8 tmp = 0xff;
		104	u8 Timeout = 0;
		105	u16 a = 0;
		106
		107
		108	#ifdef SSC_RX_FIFO
		109	SSC_ClearRxFifo();
		110	#endif
		111	SSC_Disable(); // disable chipselect
		112	SSC_PutChar(0xFF); // Send 8 Clocks to the sdcard while card is not selected.
		113	SSC_Enable(); // enable chipselect.
		114
		115	if (*CMD == 0x41) _delay_ms(10); // if command is CMD0 generate a short delay.
		116
		117	for (a = 0;a<0x06;a++) // send the command sequence to the sdcard (6 bytes)
		118	{
		119	SSC_PutChar(*CMD++);
		120	}
		121
		122	#ifdef SSC_RX_FIFO
		123	SSC_ClearRxFifo();
		124	#endif
		125	while (tmp == 0xff) // Wait for response from sdcard.
		126	{
		127	tmp = SSC_GetChar();
		128	if (Timeout++ > 100)
		129	{
		130	break; // or timeout.
		131	}
		132	}
		133
		134	return(tmp);
		135	}
		136
		137
		138
		139
		140	//________________________________________________________________________________________________________________________________________
		141	// Funtion: SDC_PutSector(void);
		142	//
		143	// Description: This function writes one sector of data to the SSC
		144	//
		145	//
		146	// Returnvalue: none
		147	//________________________________________________________________________________________________________________________________________
		148
		149	u8 SDC_PutSector(u32 addr,u8*Buffer)
		150	{
		151	u8 tmp;
		152	u8 CMD[] = {0x58,0x00,0x00,0x00,0x00,0xFF};
		153
		154	addr = addr << 9; // convert sectoradress to byteadress
		155
		156	CMD[1] = ((addr & 0xFF000000) >>24 );
		157	CMD[2] = ((addr & 0x00FF0000) >>16 );
		158	CMD[3] = ((addr & 0x0000FF00) >>8 );
		159
		160	tmp = SDC_PutCommand (CMD); // send command to sdcard.
		161	if (tmp != 0)
		162	{
		163	return(tmp);
		164	}
		165
		166	#ifdef SSC_RX_FIFO
		167	SSC_ClearRxFifo();
		168	#endif
		169	for (u8 a=0;a<100;a++) // wait until sdcard is ready
		170	{
		171	SSC_GetChar();
		172	}
		173
		174	SSC_PutChar(0xFE); // send start of header to the SSC
		175
		176	for (u16 a=0;a<512;a++) // transmitt one sector (normaly 512bytes) of data to the sdcard.
		177	{
		178	SSC_PutChar(*Buffer++);
		179	}
		180
		181	SSC_PutChar(0xFF); // write two bytes of crc to the sdcard (not used in spi-mode)
		182	SSC_PutChar(0xFF);
		183	#ifdef SSC_RX_FIFO
		184	SSC_ClearRxFifo();
		185	#endif
		186
		187	while (SSC_GetChar() != 0xff){}; // wait untile the sdcard is ready.
		188
		189	SSC_Disable(); // disable sdcard.
		190
		191	return(0);
		192	}
		193
		194
		195
		196	//________________________________________________________________________________________________________________________________________
		197	// Funtion: SDC_GetSector(u32 addr,u8*Buffer);
		198	//
		199	// Description: This function reads one sector of data from the SSC
		200	//
		201	//
		202	// Returnvalue: none
		203	//________________________________________________________________________________________________________________________________________
		204
		205	u8 SDC_GetSector(u32 addr,u8*Buffer)
		206	{
		207	u8 CMD[] = {0x51,0x00,0x00,0x00,0x00,0xFF};
		208
		209	addr = addr << 9; // convert sectoradress to byteadress.
		210
		211	CMD[1] = ((addr & 0xFF000000) >>24 );
		212	CMD[2] = ((addr & 0x00FF0000) >>16 );
		213	CMD[3] = ((addr & 0x0000FF00) >>8 );
		214
		215	SDC_GetBlock(CMD,Buffer,512); // read specified sector from sdcard.
		216
		217	return(0);
		218	}
		219
		220
		221
		222	//________________________________________________________________________________________________________________________________________
		223	// Funtion: SDC_GetBlock(void);
		224	//
		225	// Description: This function reads one block of data of s16 bytes from the SSC.
		226	//
		227	//
		228	// Returnvalue: the function returns 0 if the initialisation was successfull otherwise the function returns an errorcode.
		229	//________________________________________________________________________________________________________________________________________
		230
		231	void SDC_GetBlock(u8CMD,u8Buffer,u16 Bytes)
		232	{
		233	if (SDC_PutCommand (CMD) != 0) // Send command to the sdcard.
		234	{
		235	return;
		236	}
		237
		238	#ifdef SSC_RX_FIFO
		239	SSC_ClearRxFifo();
		240	#endif
		241	while (SSC_GetChar() != 0xfe){}; // wait until the sdcard is ready to transmitt data.
		242
		243	for (u16 a=0;a<Bytes;a++) // read the block from the SSC (normaly 512Bytes)
		244	{
		245	*Buffer++ = SSC_GetChar();
		246	}
		247
		248	SSC_GetChar(); // Read two bytes CRC- checksum (not used in spi-mode)
		249	SSC_GetChar();
		250	SSC_Disable(); // disable sdcard.
		251	}
		252
		253
		254

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