SD Card SPI Init Problem (ACMD41 & CMD1 always return 0x01)

I forgot to mention that CS is high when I send the first 80 pulses...

The above mentioned is absolutely true. I have initialised my uSD card, with the same procedure. Once CRC is sent, start polling for Idle state. After some dummy bytes(0xFF), you will get expected response as 0x00.
 
For more details of the code, goto www.silabs.com. I hope Microchip won't mind this. :-) :-)
 
 

Well by setting j=255 in the test for a1==0x01 you're breaking out of the for loop immediately. If the card actually takes a few more 8-clock cycles before it comes out of idle you'll miss it. Try removing the j=255 statement completely.
 
Mark.

OK, it's looking like the commands are failing. Note that the card will enter idle mode from power up as well as from CMD0, so maybe the SPI mode is wrong? What are the CKE, SPE and CKP bits set too? If the wrong edge is being used to capture data the result might be flaky, sometimes it works sometimes it doesn't.
 
Mark.

Hi markp,

I've already investigated this, and I think my SPI hardware is well initialized. Here is my SPI init code. I'm using the SPI2 in the PIC18F26J50 (I can't use SPI1 because the pins are hardmapped with USART1.....). The only thing I do before this is to initialize USART1 (without interrupt). I know that I should embed ASM code to initialize the PPS (as stated in the datasheet), but C code with interrupt disabled seems to work....

void init_MMC(void)
{

    TRISAbits.TRISA6 = 0;        // CS output
    PORTAbits.RA6 = 1;            // Deassert CS#
    PutS_USART("MMC Init\n");

    ANCON1bits.PCFG11 = 1;     // AN11 configured as a digital port

    TRISCbits.TRISC0 = 0;    // SDO output
    TRISCbits.TRISC1 = 1;    // SDI input
    TRISCbits.TRISC2 = 0;    // SCK output

    // Peripheral Pin Select (PPS) configuration for SPI2
    INTCONbits.GIE = 0;
    EECON2 = 0x55;
    EECON2 = 0xAA;
    PPSCON = 0;

    RPOR11 = 9;            // RP11 = SDO2
    RPOR13 = 10;        // RP13 = SCK2
    RPINR21 = 12;        // RP12 = SDI2
    RPINR22 = 13;        // CLKOUT also an input (see datasheet note)

    INTCONbits.GIE = 1;
    EECON2 = 0x55;
    EECON2 = 0xAA;
    PPSCON = 1;

    SSP2STATbits.SMP = 0;        // input is valid in the middle of clock
    SSP2STATbits.CKE = 0;        // rising edge is data capture
    SSP2CON1bits.CKP = 1;        // high value is passive state
    SSP2CON1bits.SSPM3 = 0;        // speed f/64(312kHz), Master
    SSP2CON1bits.SSPM2 = 0;
    SSP2CON1bits.SSPM1 = 1;
    SSP2CON1bits.SSPM0 = 0;
    SSP2CON1bits.SSPEN = 1;        // enable SPI
   
    // start MMC in SPI mode
    for(i=0; i < 10; i++)
    {   
        SPI(0xFF);        // send 10*8=80 clock pulses
    }


     (....)
}


And then I reassert CS, send CMD0, ....


So the SD card will enter idle mode right from power up? The card will respond 0x01 after CMD1 even if I don't send CMD0 before? Even if I don't send 80 pulses?


My hardware is pretty simple: I've soldered a jumper on my SD card, so I can plug it in my breadboard. Here is pinout of my SD card with the PIC:

1) CS# (10k pull-up to Vdd) -> pin10 (RA6)
2) DI (10k pull-up to Vdd) -> pin11 (SDO)
3) Vss Ground
4) Vdd (supply voltage, 3.3V, same LDO as the PIC, well decoupled)
5) CLK (10k pull-up to Vdd) -> pin13 (SCK)
6) Vss2
7) DO (10k pull-up to Vdd) -> pin12 (SDI)




Why the commands are failing?

Very strange....

herambmp: What do you mean by the bit 7 of the response? The card always respond 7 low bits and 1 high bit... By the way, I've tried what you told me to send 80 pulses with CS# deasserted (high level) between each command (CMD0 - 80pulses - CMD1 - 80pulses - CMD1 - 80 pulses - CMD1 - .....) and its not working (0x01 reponse...)......

I'Ve not tried another card yet, i'll do it today!

Thanks

OK, i've tried with a 4gb SDHC sd card from Lexar, and the card respond to my CMD8:

      SPI(0x48);    // CMD8
      SPI(0x00);    //
      SPI(0x00);
      SPI(0x01);    // HVS
      SPI(0xAA);    // test pattern
      SPI(0x87);    // right checksum for CMD8

The give me a R1 response : 0x01
followed by the 4 argument bytes (echoed back) : 0x00 0x00 0x01 0xAA
This is OK according to the Secure Digital datasheet.

When I try with my other card (the first one, 128Mb SD card, not SDHC), I have a R1 response of 0x05 (0b00000101), meaning that its an illegal command. This is normal since it is not a SDHC card, and does not recognize the CMD8 cmd.

With my Lexar 4Gb SDHC card, when I send CMD8 with the wrong CRC (for example, 0x88), the card respond with a R1 response of 0x09 (0b00001001), meaning that there is a communication CRC error. This is normal...

This show me that the card is OK, and the commands seem to be interpreted by the card...

The ACMD1 command is still responding 0x01 !!!!!!

Vdd of 3.3V is fine for a SD card?

Thanks guys!

Hey guys.... IT WORKED!

You have to READ the whole SD Datasheet in order to be able to init a SDHC card....


For your information, the problem was my ACMD41 argument, I have to set the HCS bit in order to tell the card that the host support High Capacity cards...

In my ACMD41 loop:

   for (test = 0; test < 100; test++)
   {
       PORTAbits.RA6 = 0;    // Assert CS#

       SPI(0xFF);
       SPI(0x77);    // CMD55
       SPI(0x00);   
       SPI(0x00);
       SPI(0x00);
       SPI(0x00);
       SPI(0xFF);

       a1 = SPI(0xFF);
       a2 = SPI(0xFF);

       PORTAbits.RA6 = 1;    // DeAssert CS#
       SPI(0xFF);
       PORTAbits.RA6 = 0;    // Assert CS#

       SPI(0xFF);
       SPI(0x69);    // CMD41
       SPI(0x40);    // HCS=1
       SPI(0x00);
       SPI(0x00);
       SPI(0x00);
       SPI(0xFF);

       for (j = 0; j < 150; j++)
       {
           // waiting for 00h from card
           a1 = SPI(0xFF);
           if (a1 == 0x00)
           {
               // card init OK
               PORTAbits.RA6 = 1;    // DeAssert CS#
               SPI(0xFF);
               PutC_USART("card init OK");
               return;
           }
           else
           {
               //wait
           }
       }

       PORTAbits.RA6 = 1;    // DeAssert CS#
   }


And by the way, it is MANDATORY to issue CMD8 before ACMD1 in order to init the card.

Thanks you guys, your help was very appreciated!

Regards,

Felix Gourdeau

Congrats !!! Keep going....

check out the projects page on my web site for some sample (working) schematics for integrating SD/MMC cards with 5 volt and 3.3 volt PICs

Felix,

Did you ever eperience the problem of the SD card pulling down your CLK, SDO and SDI lines?  I just started this same type of project and whenever I connect the SD card in the circuit it pulls all my lines down to to around .2-.5V  I have 10K pull up resistors on SDI and SDO and everything is connected correctly.  Any suggestions?