Hello all,

Has anyone had experience in writing the SDIO controller car
software? I am working on a SDIO controller software using the SP
interface. The controller being used is PIC.

And I am not able to find a SDIO Host controller for testing m
card.

And I am unable to find which SPI mode is used for communication?
and whether the SD 1-bit mode implementation is mandatory for testing m
card. If so, then what is the specification for the SD protocol and how i
works?

Please help me out.

Many Thanks

Munnangi

munnangi wrote:
I have done this on an ARM LPC-2378 dev board. It's all written in C, but
it works ok with the one and only (16MB) SD card I own. I'm pretty sure
that I am violating the 400KHz data-rate speed limit when initializing the
card, but it seems to work anyway.

??? Do you want to use SPI mode for communicating with SD card or the
really fast interface? On the ARM, the host controller is built in as a
peripheral device. I haven't used that part yet, only bit banging ordinary
I/O pins to simulate an SPI transceiver. Or, are you asking where to get a
socket to mate with the card?

It's hard to find because they want you to pay for the specification. I was
able to work enough of it out from a public (read as highly stripped down)
version of the specification and from using SD (and MMC) card
datasheets/app-notes from various manufacturers.

munnangi wrote:
Ok, I think I'm starting to get it. You are creating a device that plugs
into a MMC/SD/SDIO socket. I'm kinda slow.


I used an LPC-2378STK dev board from www.olimex.com. The actual SPI
controller in the dev board is not connected to the MMC socket pins. There
is an internal high speed controller that can generate the MCICLK, MCIDAT0-3
etc signals, but I have not used that module yet. I used the pins as
general I/O pins and bit-banged the SPI signal to the card. Slow and crude,
but I learned from it (which was my goal). I'm into the ARM stuff right now
(but I've done plenty of PIC stuff), but Olimex makes plenty of other dev
boards with MMC sockets and various CPUs, including PIC. Their PIC-USB-STK
has an MMC socket and an 18F4550 processor on it, along with a bunch of
other functionality.

That's about all I know.

Your welcome, hope it helps.