On 8 Dec 2006 00:47:34 -0800, "Boki" <bokiteam@ms21.hinet.net> wrote:> >PeteS �g�D�G > >> Nevo wrote: >> >> > SD cards must support the SPI interface. So any microcontroller with a built >> > in SPI interface can control an SD card. >> > >> > You can download the MMC card spec from SanDisk to get the details. >> > >> >> The MMC spec is not the same as the SD spec, unfortunately. One can get >> a copy of the minimal SD spec for free but not the whole spec without >> joining the club. The entire spec is necessary to fully implement SD. >> >> I am using a device from Winbond that supports SD and SDIO, but I had >> to sign NDAs to get the source. I have no doubt you will run into the >> same issue. >> >> Cheers >> >> PeteS >> > >Thanks a lot, I think NDA is not an issue. :) > >Best regards, >Boki.SD is a superset of MMC, and AFAIK all SD cards ( except maybe the very big ones) can be treated as MMC cards unless you want the SD-specific features. I think you have to pay significant $ to join the SD card club to get the formal SD specs
Need a SD (memory card) controller chip.
Started by ●December 6, 2006
Reply by ●December 8, 20062006-12-08
Reply by ●December 8, 20062006-12-08
"Mike Harrison" <mike@whitewing.co.uk> wrote in message news:k4bin21a3ds5beijoi2r9dg8dlhn2fvacd@4ax.com...> On 8 Dec 2006 00:47:34 -0800, "Boki" <bokiteam@ms21.hinet.net> wrote: > >> >>PeteS �g�D�G >> >>> Nevo wrote: >>> >>> > SD cards must support the SPI interface. So any microcontroller with a >>> > built >>> > in SPI interface can control an SD card. >>> > >>> > You can download the MMC card spec from SanDisk to get the details. >>> > >>> >>> The MMC spec is not the same as the SD spec, unfortunately. One can get >>> a copy of the minimal SD spec for free but not the whole spec without >>> joining the club. The entire spec is necessary to fully implement SD. >>> >>> I am using a device from Winbond that supports SD and SDIO, but I had >>> to sign NDAs to get the source. I have no doubt you will run into the >>> same issue. >>> >>> Cheers >>> >>> PeteS >>> >> >>Thanks a lot, I think NDA is not an issue. :) >> >>Best regards, >>Boki. > > SD is a superset of MMC, and AFAIK all SD cards ( except maybe the very > big ones) can be treated as > MMC cards unless you want the SD-specific features. > > I think you have to pay significant $ to join the SD card club to get the > formal SD specsSD memory cards specs were based on MMC specs but MMC specs have progressed many versions since then and SD have moved on to v2.0 too. I think there are MMC cards that can work in SD slots but there are no guarantees anymore. I've only done a two minute test with an MMC card in my own SD card interface (for an analytical instrument). It was not recognised - haven't had time to find out why. Peter
Reply by ●December 8, 20062006-12-08
In comp.arch.embedded, Peter Dickerson <firstname.lastname@REMOVE.tesco.net> wrote:> "Mike Harrison" <mike@whitewing.co.uk> wrote in message > news:k4bin21a3ds5beijoi2r9dg8dlhn2fvacd@4ax.com... >> >> SD is a superset of MMC, and AFAIK all SD cards ( except maybe the very >> big ones) can be treated as >> MMC cards unless you want the SD-specific features. >> >> I think you have to pay significant $ to join the SD card club to get the >> formal SD specs > > SD memory cards specs were based on MMC specs but MMC specs have progressed > many versions since then and SD have moved on to v2.0 too. I think there are > MMC cards that can work in SD slots but there are no guarantees anymore. > I've only done a two minute test with an MMC card in my own SD card > interface (for an analytical instrument). It was not recognised - haven't > had time to find out why.I think you've got it backwards. SD cards wil work in MMC slots in most cases. If an MMC card works in an SD slot it is only because the device supports MCC as well (or only uses MMC mode, even for SD cards, this avoids the NDA issue). Your instrument seems to support SD mode only, so MMC will not work. -- Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)
Reply by ●December 8, 20062006-12-08
I dont think he will run into the same issues , nor will i .
The market will be free , or it will die , take your pick ....
Patents hold society hostage by those who only copyied
others , but got to patent office first !
Can You say Bill Gates !
Reply by ●December 9, 20062006-12-09
"Stef" <stef33d@yahooI-N-V-A-L-I-D.com.invalid> wrote in message news:893c$45794128$54f63171$29655@publishnet.news-service.com...> In comp.arch.embedded, > Peter Dickerson <firstname.lastname@REMOVE.tesco.net> wrote: >> "Mike Harrison" <mike@whitewing.co.uk> wrote in message >> news:k4bin21a3ds5beijoi2r9dg8dlhn2fvacd@4ax.com... >>> >>> SD is a superset of MMC, and AFAIK all SD cards ( except maybe the very >>> big ones) can be treated as >>> MMC cards unless you want the SD-specific features. >>> >>> I think you have to pay significant $ to join the SD card club to get >>> the >>> formal SD specs >> >> SD memory cards specs were based on MMC specs but MMC specs have >> progressed >> many versions since then and SD have moved on to v2.0 too. I think there >> are >> MMC cards that can work in SD slots but there are no guarantees anymore. >> I've only done a two minute test with an MMC card in my own SD card >> interface (for an analytical instrument). It was not recognised - haven't >> had time to find out why. > > I think you've got it backwards. SD cards wil work in MMC slots in most > cases. If an MMC card works in an SD slot it is only because the device > supports MCC as well (or only uses MMC mode, even for SD cards, this > avoids the NDA issue).The standard SD card is thicker than the MMC card so there ought to be a mechanical problem with putting SD into an MMC-only slot.> Your instrument seems to support SD mode only, so MMC will not work.I have now found a pointbin the SD spec that says if such-and-such fails then treat as MMC card. So it looks like need to look more carefully at MMC if I want to support that. Peter
Reply by ●December 9, 20062006-12-09
In comp.arch.embedded, Peter Dickerson <firstname.lastname@REMOVE.tesco.net> wrote:> "Stef" <stef33d@yahooI-N-V-A-L-I-D.com.invalid> wrote in message > news:893c$45794128$54f63171$29655@publishnet.news-service.com... >> >> I think you've got it backwards. SD cards wil work in MMC slots in most >> cases. If an MMC card works in an SD slot it is only because the device >> supports MCC as well (or only uses MMC mode, even for SD cards, this >> avoids the NDA issue). > > The standard SD card is thicker than the MMC card so there ought to be a > mechanical problem with putting SD into an MMC-only slot.Ah, forgot about the thickness issue. But why would anyone implement an mmc only slot instead of one that will also accept SD? These days, SD is a lot more common than MMC and limiting yourself to MMC does not seem logical. Maybe in rare cases where the 0.7mm difference is a problem, it's an option but then you could also investigate mini SD and thin SD. -- Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)
Reply by ●December 14, 20062006-12-14
> Boki wrote: > > Hi All, > > > > I need a SD memory card controller chip, I also need to porting some > > MCU code, and need UART interface, low speed as 9.6K is enough. > > > > Best regards, > > Boki.Did you find an SD Card Host controller? I am looking for one and could use some help. The dosonchip looks interesting but i think would be too slow. I need a concurrent write of 1Mbytes/s and a read of 2Mbytes/s. A USB to SD card bridge would be OK. or a SD Card Host controller with a A/D bus. I need to keep the cost <$10 Thanks Joe
