Lpc2000

Look under the SPI section in the sandisk manual. I use ACMD41 as this 
is the recommended method followed by CMD58 to read the OCR. One little 
thing I do different is to pad the start of a CMD with a couple of dummy 
reads (same as writing 0xFF). I have implemented an SD driver and FAT16 
successfully on the 2106 as well as the 2138 and tested this on about 5 
different types of SD cards to date.

BTW, when you power-down the supply just make sure all the SD I/O lines 
are taken down to VSS as well.

*Peter*


armqamp wrote:

>Hello,
>
>I'm trying to make an SD card to work with the lpc2106 and later want
>to implement FAT.
>The problem is I don't get any response of the SD card when I try to
>initialize it.
>
>Maybe somebody can disover what I'm doing wrong?
>
>here is the code:
>
>@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
>
>void ActivateSD(void){
>	
>	unsigned int ii=0;
>	unsigned char resp, i;
>	unsigned char status;
>	
>	print("Activating SD Card....\n\n");
>
>	// Turn off SD Card
>	SD_power_off;
>
>	// Wait for power to really go down
>	for(ii = 0; ii; ii++);
>	for(ii = 0; ii; ii++);
>	for(ii = 0; ii; ii++);
>	for(ii = 0; ii; ii++);
>
>	// Turn on SD Card
>	SD_power_on;
>
>	// Wait for power to really come up
>	for(status = 0; status < 10; ++status)
>	{
>		for(ii = 0; ii; ii++);
>		for(ii = 0; ii; ii++);
>		for(ii = 0; ii; ii++);
>		for(ii = 0; ii; ii++);
>	}
>	
>	
>	
>	
>	
>	for(i=1; i<=10; i++){	                //try 10 times to wake up the card
>		
>		SD_disable;			//CS high
>		
>		InitSequence();			//send 80 clocks
>		
>		SD_enable;			//CS low
>		
>		SD_SendCommand(CMD0,0,0,0,0); //send Reset command
>		
>		resp = SD_Response();
>		if( resp == 0x01 ){          //wait for R1 response to be 0x01
>			break;
>		}
>		else{
>		
>		}
>		
>	}
>	
>	spiSendByte(0xFF);		   // Response received, send the required 8
>clocks after the response to finish up (page 5-6 Sandisk Manual)
>
>	
>	if(i>10){
>		SD_disable;
>		print("SD activation failed\n");
>	}
>	else{
>		print("SD activation successfully\n");
>		
>		while( resp != 0x00){	                 //try sending CMD1 until
>response R1 is 0x00
>			SD_SendCommand(CMD1,0,0,0,0);	 //activate card initialization process
>			resp = SD_Response();
>			spiSendByte(0xFF);	         //send required 8 clocks
>			if(resp==0x00){		         // Ready
>				print("SD successfully activated!!!\n");
>				break;
>			}
>		}
>		
>		if(resp != 0x00){
>			print("Error: ");
>			print("0x"); printnum(16, 8, 0, '0', resp); print("\n");
>		}
>		
>	}
>	print("\n-------end-----------\n");
>}
>
>
>unsigned char SD_Response(void) {
>	unsigned char 	i;
>	unsigned char 	resp;	
>	
>	for(i=0; i<10; i++) {
>		resp = spiGetByte();
>		if(resp != 0xFF) {
>			return resp;
>		}
>	}		
>	return 0xFF;
>}
>
>void SD_SendCommand(unsigned char command, unsigned char arg_a,
>unsigned char arg_b, unsigned char arg_c, unsigned char arg_d) {	
>	spiSendByte(command);
>	spiSendByte(arg_a);
>	spiSendByte(arg_b);
>	spiSendByte(arg_c);
>	spiSendByte(arg_d);
>	spiSendByte(0x95);				// correct CRC for first command in SPI after
>that CRC is ignored, so no problem with always sending 0x95
>}
>  
>