Editing SD card (section)

===Embedded systems===
[[File:Arduino Ethernet Shield (pre-production sample).jpg|thumb|A shield ([[daughterboard]]) that gives [[Arduino]] prototyping microprocessors access to SD cards]]

In 2008, the SDA specified Embedded SD, "leverag[ing] well-known SD standards" to enable non-removable SD-style devices on printed circuit boards.<ref>{{cite web|title=Embedded SD|publisher=SD Association|url=http://www.sdcard.org/developers/overview/embedded_sd/|access-date=2011-11-30|archive-date=2011-11-21|archive-url=https://web.archive.org/web/20111121065447/https://www.sdcard.org/developers/overview/embedded_sd/|url-status=live}}</ref> However this standard was not adopted by the market while the [[MultiMediaCard|MMC]] standard became the de facto standard for embedded systems. SanDisk provides such embedded memory components under the iNAND brand.<ref>{{cite web|title=iNAND Embedded Flash Drives|publisher=SanDisk|url=http://www.sandisk.com/business-solutions/inand-embedded-flash-drives|access-date=2011-11-30|archive-date=2011-12-25|archive-url=https://web.archive.org/web/20111225022347/http://www.sandisk.com/business-solutions/inand-embedded-flash-drives|url-status=live}}</ref>

While some modern [[microcontroller]]s integrate SDIO hardware which uses the faster proprietary four-bit SD bus mode, almost all modern microcontrollers at least have [[Serial Peripheral Interface Bus|SPI]] units that can interface to an SD card operating in the slower one-bit SPI bus mode. If not, SPI can also be emulated by [[bit banging]] (e.g. a SD card slot [[soldered]] to a [[Linksys]] [[WRT54G|WRT54G-TM]] router and wired to [[General-purpose input/output|GPIO]] pins using [[DD-WRT]]'s [[Linux kernel]] achieved only {{Nowrap|1.6 [[Mbit/s]]}} throughput).<ref>{{cite web |url=http://www.dd-wrt.com/wiki/index.php/Linksys_WRT54G-TM_SD/MMC_mod |title=Linksys WRT54G-TM SD/MMC mod – DD-WRT Wiki |publisher=Dd-wrt.com |date=2010-02-22 |access-date=2010-08-22 |archive-date=2010-09-01 |archive-url=https://web.archive.org/web/20100901020001/http://www.dd-wrt.com/wiki/index.php/Linksys_WRT54G-TM_SD/MMC_mod |url-status=live }}</ref>