Show Posts
1
General Discussion / Does the C860 have SDIO?
« on: September 22, 2004, 04:57:27 am »
I googled around some.
Zaurus C860 runs on PXA255, Intel has documentation available online (see http://www.intel.com/design/pca/prodbref/252780.htm ). PXA255 has only basic MMC/SPI.
SDcard.org has partial SDIO specifications available online (see http://www.sdcard.org/sdio/index.html ) SDIO has three operating modes, SPI, 1-bit and 4-bit. I reckon SPI is a backward-compatability mode, which luckily would mean most SDIO cards should work with PXA255. (I hope zaurus has the interrupt pin connected, as specified in chapter 2.2.1..)
Given this, SPI is the slowest operating mode, and MMC bus has a lower maximum operating frequency (20MHz vs 25MHz). Running WLAN-SDIO on substandard SPI mode is bound to have poor performance. SDIO devices that aren't that bandwidth-hungry should work nicely though, like GPS, modems and bluetooth.
Zaurus C860 runs on PXA255, Intel has documentation available online (see http://www.intel.com/design/pca/prodbref/252780.htm ). PXA255 has only basic MMC/SPI.
SDcard.org has partial SDIO specifications available online (see http://www.sdcard.org/sdio/index.html ) SDIO has three operating modes, SPI, 1-bit and 4-bit. I reckon SPI is a backward-compatability mode, which luckily would mean most SDIO cards should work with PXA255. (I hope zaurus has the interrupt pin connected, as specified in chapter 2.2.1..)
Given this, SPI is the slowest operating mode, and MMC bus has a lower maximum operating frequency (20MHz vs 25MHz). Running WLAN-SDIO on substandard SPI mode is bound to have poor performance. SDIO devices that aren't that bandwidth-hungry should work nicely though, like GPS, modems and bluetooth.