Two 4 bit SDIO buses on Kinetis K60

[alexandersavche]

Hi, everyone. I need to use two SDIO bus on the same Kinetis K60 board. One for SD card, another for Wi-Fi module with SDIO interface. Is is t posible to use GPIO as a BUS like SDIO? I want to use SD card in 4 bit mode.

[larryc]

Alex

This is controlled by the Port Control Module on the K60, which selects which alternate configurations are in use.  Those are listed in the Signal Multiplexing and Pin Assignments section in Document K60P144M120SF3.

I looked briefly and I saw only one SDHC assignable in the table.

Good luck,

Larry

[alexandersavche]

I saw it. But I want to use one dedicated bus and one additional with free pins (mat be it will software emulated bus).

[Jorge_Gonzalez]

Hello Alexander Savchencko:

There is only one SDHC module in the K60, so you are correct, the solution would be a software emulated bus. I guess you could emulate the SDIO bus by using SPI peripheral. Unfortunately we do not have an example for this.

Maybe you can look at the implementation of MSD host from the Freescale USB stack v4.1.1 (download from USB Stack|Freescale). The USB MSD example has an option to use SPI interface to talk to an SD card.

Regards!

Jorge Gonzalez