I need to interface a wifi chip to my ARM 9 board, it does not have in built SDIO so i am thinking to interface via bit banging.


  1. Is it possible to interface SDIO via bit banging
  2. If not then any converter chip to convert SDIO to other protocol.
  3. If yes then any source code link will be helpful.
  • 1
    \$\begingroup\$ Q1 - Yes. Q2 - Shopping is off-topic. Q3 - links to offsite info are discouraged (also off-topic - too broad). And multiple Q's in one are also discouraged. \$\endgroup\$
    – brhans
    Commented Dec 8, 2016 at 16:31

1 Answer 1


SDIO cards must work with the SPI-only interface you know from SD storage cards.

So, yes, bitbanging is possible, and easy, but you'd normally use the SPI controllers that every ARM I've ever met comes with.

See Chapter 2 of the SDIO Simplified Specification.

Your ARM SoC vendor very likely has Linux kernel drivers for their SPI controllers to make that easier.

Also, check twice with the manufacturer of your WiFi chip. If it behaves anything like other WiFi interfaces, they probably have network card drivers of their own that build atop of the SPI kernel infrastructure.

  • \$\begingroup\$ Thanks , Yes it has linux kernal driver, and has inbuilt SPI , but that all are use already with other devices. So do i need to do SPI bit banging method for SDIO interface \$\endgroup\$ Commented Dec 8, 2016 at 16:51

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