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From: Murray R. Van Luyn on 1 Dec 2008 01:57
Hi,

I'm trying to initialise a 2GB Transcend SD card with an AT89C51AC2.

I send CMD0 and get a 0x01 response. It's initialising...

Then I send 10 CMD55 messages and get no valid response (0xFF) each time.
I don't know why I don't get a 0x01 response here until the card has
finished initialising?

Sound familiar to anyone?

Regards,
Murray R. Van Luyn.


From: Peter Jakacki on 1 Dec 2008 03:06
Murray R. Van Luyn wrote:
> Hi,
>
> I'm trying to initialise a 2GB Transcend SD card with an AT89C51AC2.
>
> I send CMD0 and get a 0x01 response. It's initialising...
>
> Then I send 10 CMD55 messages and get no valid response (0xFF) each time.
> I don't know why I don't get a 0x01 response here until the card has
> finished initialising?
>
> Sound familiar to anyone?

You send CMD0 and that's fine but you need to send ACMD41 which is
CMD55+CMD41 combo. I don't put a limit on the number of times I do this
but depend upon a timeout instead. It depends upon the card.

*Peter*

From: Murray R. Van Luyn on 1 Dec 2008 03:45
Thanks Peter.

It seems that I'm going to get a 0x01 response no matter how many times I
issue CMD0.

Also, it seems that I'm going to get an invalid response (0xFF) no matter
how many times I then issue CMD55.

Vexing!

Regards,
Murray R. Van Luyn.

"Peter Jakacki" <peterjakacki(a)gmail.com> wrote in message
news:dWMYk.2320$Et1.1805(a)news-server.bigpond.net.au...
> Murray R. Van Luyn wrote:
>> Hi,
>>
>> I'm trying to initialise a 2GB Transcend SD card with an AT89C51AC2.
>>
>> I send CMD0 and get a 0x01 response. It's initialising...
>>
>> Then I send 10 CMD55 messages and get no valid response (0xFF) each time.
>> I don't know why I don't get a 0x01 response here until the card has
>> finished initialising?
>>
>> Sound familiar to anyone?
>
> You send CMD0 and that's fine but you need to send ACMD41 which is
> CMD55+CMD41 combo. I don't put a limit on the number of times I do this
> but depend upon a timeout instead. It depends upon the card.
>
> *Peter*
>


From: Peter Jakacki on 1 Dec 2008 03:55
Murray R. Van Luyn wrote:
> It seems that I'm going to get a 0x01 response no matter how many times I
> issue CMD0.
>
> Also, it seems that I'm going to get an invalid response (0xFF) no matter
> how many times I then issue CMD55.

Yes, of course, but read my previous post. BTW, 01 is the correct
response for CMD0 then you move on to Acmd41 not CMD55 .

*Peter*
From: Murray R. Van Luyn on 1 Dec 2008 04:18
Hi Peter,

Yes, I've issued CMD0, then CMD55 as a precursor to ACMD47. I never got past
the CMD55 which results in the repeated invalid response. If I issue CMD0
followed by ACMD47 I get the same invalid responses.

I've managed to get the SD card to respond to an MMC card CMD0 then CMD1
initialisation sequence. That won't do as I'm writing code specifically for
an SD card. Crumbs!

Regards,
Murray R. Van Luyn.

"Peter Jakacki" <peterjakacki(a)gmail.com> wrote in message
news:2ENYk.2333$Et1.1594(a)news-server.bigpond.net.au...
> Murray R. Van Luyn wrote:
>> It seems that I'm going to get a 0x01 response no matter how many times I
>> issue CMD0.
>>
>> Also, it seems that I'm going to get an invalid response (0xFF) no matter
>> how many times I then issue CMD55.
>
> Yes, of course, but read my previous post. BTW, 01 is the correct response
> for CMD0 then you move on to Acmd41 not CMD55 .
>
> *Peter*


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