[PIC] sdhc initialization (cmd 41 error)

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anjalimidhuna

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sdhc initializtaion(cmd 41 error)

hi,
i m facing a trouble while initializing sdhc 4gb card.
successfully responded till cmd41.i got responds as 0xff for this particular command .

i send
CMD0 -- res:0x01
CMD8 -- res:0x01AA
CMD55 res:0x01
CMD41 res:0xFF
 

Re: sdhc initializtaion(cmd 41 error)

SPI lines have pullups ? What Compiler are you using and what microcontroller ?
 

Re: sdhc initializtaion(cmd 41 error)

no pull ups in spi lines.. i m using pic18f4550 with hitech-c compiler for pic18
 

Re: sdhc initializtaion(cmd 41 error)

Pull ups needed. Zip and post full MPLAB project files. If pins used for SPI has ADC functions then you have to configure ANSELx or ADCONx registers and make those pins digital IO pins.
 

Re: sdhc initializtaion(cmd 41 error)

please find the attachment.

- - - Updated - - -

recently i found
An SDIO aware host sends CMD5 prior to the CMD55/ACMD41 pair, and thus would receive a valid OCR in
the R4 response to CMD5 and continue to initialize the card
Click to expand...
from one pdf available in the Google .i tried this waiting for a non zero value and got the correct response but still CMD41 respond with 0xFF. it find strange !!
 

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  • sdhc_test.zip
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Re: sdhc initializtaion(cmd 41 error)

actually i experimented all these specifications.but no use. pull ups in spi line didn't find use.
my card includes SD spec 3.0. as per the reference
 

Re: sdhc initializtaion(cmd 41 error)

It is not necessary to use pull-up's on all SPI lines. But you need to have a pull-up on chipselect (if it is active low) to maintain in high. Even if you permenantly enable the communication on SPI lines. Then drive chip select to 0 always so pull up will not be needed that time.
 
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Re: sdhc initializtaion(cmd 41 error)

anjalimidhuna said:
actually i experimented all these specifications.but no use. pull ups in spi line didn't find use.
my card includes SD spec 3.0. as per the reference
Click to expand...

Pullup is necessary on the MISO line to prevent floating because the sd card puts in high impedance state this line when no communication is running. Other lines are usually set as outputs, so no pullups are required.
Do you put the SSEL line to high between the CMD55 and CMD41 ?
 

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