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arunb
Joined: 08 Sep 2003
Posts: 492
Location: India
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| Which card MMC or SD may be better in the long run.. |
 Posted: Thu Jun 11, 2009 10:39 pm |
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Hi,
I am trying to standardize on a design that uses a RS MMC card, I find that this card is not easily available as Nokia and Siemens stopped using them in their designs.
My question is
1. Are the SD cards more likely to be available in the future than the MMC ones ?
2. I am able to get MMC Plus cards, will the CCS drivers for the RS MMC be compatible with the MMC Plus cards ?
3. If I start using the SD Cards, will the drivers for the SD Card be compatible with microSD card ?
thanks
arunb |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Re: Which card MMC or SD may be better in the long run.. |
| Posted: Thu Jun 11, 2009 11:17 pm |
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| arunb wrote: | Hi,
I am trying to standardize on a design that uses a RS MMC card, I find that this card is not easily available as Nokia and Siemens stopped using them in their designs.
My question is
1. Are the SD cards more likely to be available in the future than the MMC ones ? |
The SD form factor is far more readily available than the MMC form factor
| Quote: | | 2. I am able to get MMC Plus cards, will the CCS drivers for the RS MMC be compatible with the MMC Plus cards ? |
Only in so far that you will have MMC basic functionality
| Quote: | | 3. If I start using the SD Cards, will the drivers for the SD Card be compatible with microSD card ? |
Yes provided the vendor of the microSD card supports the SPI mode.
SPI mode support is not a mandatory requirement for microSD cards under the SD card specification. Most microSD card vendors offer passive adapters to enable microSD cards to be used for miniSD and full size SD card applications enabling these vendors to increase their addressable market so it is unlikely these vendors will drop SPI support from their microSD products.
I develop SD/MMC based software products and have tested using my software a range of microSD cards from various vendors both standard and SDHC variants and have not found any cards that do not support SPI mode.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!!
Last edited by asmallri on Thu Jun 11, 2009 11:49 pm; edited 1 time in total |
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arunb
Joined: 08 Sep 2003
Posts: 492
Location: India
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| RE: |
| Posted: Thu Jun 11, 2009 11:23 pm |
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So SD card may be a better option??
Does one have to become member for accessing SD card specs ??
thanks
arunb |
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asmallri
Joined: 12 Aug 2004
Posts: 1634
Location: Perth, Australia
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| Re: RE: |
| Posted: Thu Jun 11, 2009 11:48 pm |
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| arunb wrote: | | So SD card may be a better option?? |
No. There is (was) no ambiguity with licensing with MMC. You only needed a license if you were actually manufacturing MMC cards. This may have changed as the MMCA Board of Directors and Executive Members have approved a motion to dissolve MMCA and transfer assets (including specifications, works in progress, copyrights and certain other assets) to the JEDEC Solid State Technology Association.
Note that the latest version of the MMC specification also dropped SPI support (obsoleted it).
| Quote: |
Does one have to become member for accessing SD card specs ??
thanks
arunb |
They offer a free light weigh version of the specification here: http://www.sdcard.org/developers/tech/sdcard/pls/
Free is a relative term. Buyer beware.
_________________
Regards, Andrew
http://www.brushelectronics.com/software
Home of Ethernet, SD card and Encrypted Serial Bootloaders for PICs!! |
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