goes in idle-mode and then in ready-mode but goes not in datatransfer mode

Memory Cards SD | microSD | CFast | CFexpress | CompactFlash
1

Hi

I try to acces a microSD 2Gb memory card

via SPI,    Clock=400KHz

I send the sequence  

CMD0

CMD8

CMD55

CMD41

CMD58

Each time I don´t get a illegal command and I see it goes in idle-mode and then in ready-mode

but after this init-sequence I try to read sector-0 but I get only zero´s exept position-511/512  AA55

This card I format it on a windows-XP machine in FAT16

So what goes wrong or whats the reason the card don´t go in datatransfer mode

Reg Paul

2

I am working with some students on a project and have had similar problems.

We have a small test jig and the command is K as shown below.

The setup is SPI mode and we are having problems with San Disk cards.  I have no reason to believe they are fake.

Here is the problem, and you can see that all but San Disk work perfectly.  Even the SDSC card is fine.

K

40 00 00 00 00 95 FF 01 <<< PNY Optima 8GB SDHC

48 00 00 01 AA 87 FF 01 00 00 01 AA

K

40 00 00 00 00 95 FF 01 <<< Lexar 4GB SDHC

48 00 00 01 AA 87 FF 01 00 00 01 AA

K

40 00 00 00 00 95 FF 01 <<< SanDisk 4GB SDHC

48 00 00 01 AA 87 FF C1 7F FF FF FF

K

40 00 00 00 00 95 FF 01 <<< SanDisk 256MB NOT SDHC

48 00 00 01 AA 87 FF 05 FF FF FF FF

K

40 00 00 00 00 95 FF 01 <<< SanDisk 32GB SDHC

48 00 00 01 AA 87 FF C1 7F FF FF FF

K

40 00 00 00 00 95 FF 01 <<< Patriot 4GB SDHC

48 00 00 01 AA 87 FF 01 00 00 01 AA

We would be happy to share any of the project with anyone interested.

texasrog@gmail.com

3

Hi

If you want I send all my source files to you, I implement  additional retry mechanisme and so on.

Also if you haven´t and goes design your schematic provide a additional power off/on fet for the micro-sd.

Somethings the Sandisk is hanging and only a power off/on give a solution to get back in communication with de micro-sd

micro-sd cards from Samsung or other manufactors does have such problems in SPI-mode.

Reg, pmoonen