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V4

port to MMC/SD

Unfortunately, I can't make the modules pC/FAT and pC/FFS freely accessible. However, I can give here a simplified version of the MMC/SD-Card Ports on the SPI-connection for miscellaneous controller.
By using this ports you can use another FileSystem on this interface and with it accessing the MMC- and SD-Cards. Or, like my tests, a MMC/SD-to-USB adapter can be realized in software. This works like an USB-Device as MassStorage (removable media) on the PC and you have access to the MMC- and SD-cards like an professional adapter in hardware (only slower, since SPI-mode and software realization).

Here a overview over the SD-Card versions:

SD card versions

Restrictions of the simplified MMC/SD-ports:
- no interrupt- or DMA-mode
- no detailed media infos
- no read / write in call-back mode
- no direct RTOS-support

download simplified pC/FAT Ports to MMC/SD (as ZIP)
(with MMCplus/HD-MMC/M-Bridge/SDHC/SDXC support)
(with optional McEx/ASSD-support)

On a porting to further controllers, additional to the SPI-speed adaptation only some parameters of the hardware must be known and to setup. This are the used PIO-pins for WP (WriteProtect), CD (CardDetect) plus the correct settings for MOSI, MISO, SCLK and /SS. Additional the matching SPI-mode 3 must be enabled.

to used SPI-mode of the controller (master)
Following diagram shows the SPI-mode, that is required for the communication with MMC- and SD-cards in the SPI-mode:


To the topic "speed"
In the following table, all important parameters of here present MMC/MMCplus/M-Bridge/SD/SDHC-cards are listed as confrontation. This illustrates quite well that the performance statements of the manufacturers speed for MMC/SD-mode is only indirect/relative with the context in SPI-mode.
The paramters Nac and Nbs are from special interest.
- Nac = maximum cycles between Read_CMD and data
- Nbs = maximum cycles between Write_CMD+data and End-of-Busy
These parameters partly fluctuate very strongly between the different cards/manufacturers. They give an information about how fast read and write of the internal storage can be really. BUT! also these values represent the respective absolute maximum-worth. That is but also on the other hand, a card with high Nbs nevertheless can possibly be faster ready with a Write-CMD, as a card with lower Nbs. However yields these statements a tendency over the cycles at most possible/expected/permissible from the respective manufacturer.

Card	MMC 16MB Infineon	MMC 32MB Infineon	MMC 64MB Transcend	MMC 128MB SanDisk	MMC 1GB Hama	MMCmicro 512MB X4store	RS-MMC 32MB SanDisk	MMCmobile 64MB Transcend
MID-OID	01-0000	01-0000	06-0000	02-0000	48-FFFF	6F-0000	02-0000	2C-0000
maxclk	20MHz	20MHz	20MHz	20MHz	20MHz	20MHz	20MHz	20(26)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	10.012	10.012	10.012	10.012	800.000	50.000	100.000	50.000
Nbs	40.048	40.048	40.048	40.048	102.400.000	1.600.000	400.000	1.600.000
maxsectors	31.424	62.720	125.440	250.880	2.007.040	1.003.520	62720	125.440
sectorsize	512	512	512	512	512	512	512	512

Card	MMCmobile 512MB Transcend	MMCmobile 1GB extreme	MMCmobile 2GB green memory	MMCmobile 2GB Kingston	MMCplus 512MB Transcend	MMC 1GB extreme	MMCplus 2GB Transcend	MMCplus 4GB Pretec
MID-OID	15-0000	00-0000	6F-0000	70-0000	1E-FFFF	4B-4342	1E-FFFF	19-5944
maxclk	20(26)MHz	20MHz	20(52)MHz	20(52)MHz	20(52)MHz	20(?)MHz	20(52)MHz	20(52)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	15.012	30.000	10.000	200.012	50.000	35.000	200.000	200.012
Nbs	1.921.536	480.000	1.280.000	25.601.536	1.600.000	1.120.000	6.400.000	25.601.536
maxsectors	1.003.520	1.935.360	1.945.600	1.983.488	990.208	2.022.912	1.981.952	1.988.096
sectorsize	512	512	1024	1024	512	512	1024	2048

Card	M-Bridge 1GB Hama	SD 16MB Panasonic	microSD 128MB Prima	SD 128MB SanDisk	SD 512MB Formel1	SD 1GB 133x SanDisk	miniSD 1GB SanDisk	microSD 1GB Hama
MID-OID	04-4450	01-4150	13-474B	03-4453	02-4D54	03-4453	03-4453	1B-4D53
maxclk	25(50)MHz	25MHz	25(50)MHz	25MHz	25MHz	25MHz	25MHz	25(50)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	10.000	5.012	50.000	15.000	2.000	15.000	15.000	802.200
Nbs	320.000	160.384	1.600.000	240.000	64.000	240.000	240.000	12.835.200
maxsectors	1.990.656	29.120	249.344	246.016	1.000.448	1.984.000	1.984.000	1.995.776
sectorsize	512	512	512	512	512	512	512	512

Card	SD 1GB Fuji	SD 1GB premium	SD 1GB 80x Transcend	SD 2GB plus USB ATTiA	microSD 2GB SanDisk	microSD 2GB Transcend	SD 2GB Kingston	SD 2GB Panasonic
MID-OID	1B-4D53	1B-4D53	1C-5653	29-4441	03-4453	1E-4241	02-4D54	01-4150
maxclk	25(50)MHz	25(50)MHz	25MHz	25(50)MHz	25MHz	25(50)MHz	25(50)MHz	25(?)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	802.200	802.200	50.000	10.000	15.000	200.000	400.000	5.012
Nbs	12.835.200	12.835.200	1.600.000	320.000	240.000	6.400.000	1.600.000	80.192
maxsectors	1.995.776	1.995.776	1.999.872	1.964.032	1.985.024	1.948.672	1.927.168	1.967.616
sectorsize	512	512	512	1024	1024	1024	1024	1024

Card	SD 2GB premium	SD 2GB Transcend	SD 2GB Ultra-II SanDisk	SD 4GB memoQ	SD      /      SDHC 4GB Transcend		SDHC 4GB Transcend	SDHC 4GB SanDisk
MID-OID	02-4D54	1B-4D53	03-4453	19-5944	1C-5653		1B-4D53	03-4453
maxclk	25(50)MHz	25(50)MHz	25MHz	25(50)MHz	25(?)MHz		25(50)MHz	25MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz		8MHz	8MHz
Nac	20.000	200.000	15.000	20.012	30.000	100.000	100.000	100.000
Nbs	640.000	6.400.000	240.000	2.561.536	120.000	250.000	250.000	250.000
maxsectors	1.921.024	1.981.440	1.931.264	1.956.352	1.967.616	7.870.464	7.811.072	7.959.552
sectorsize	1024	1024	1024	2048	2048	512	512	512

Card	SDHC 4GB Fuji	SDHC 4GB green memory	SDHC 4GB Kingston	SDHC 4GB Panasonic	SDHC 4GB Ultra-II SanDisk	SDHC 4GB Toshiba	microSDHC 4GB SanDisk	microSDHC 4GB Hama
MID-OID	1B-4D53	03-6883	02-4D54	01-4150	03-4453	02-4D54	03-4453	27-4850
maxclk	25(50)MHz	25(50)MHz	25(50)MHz	25MHz	25MHz	25(50)MHz	25MHz	25(50)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	100.000	100.000	100.000	100.000	100.000	100.000	100.000	100.000
Nbs	250.000	250.000	250.000	250.000	250.000	250.000	250.000	250.000
maxsectors	7.811.072	7.913.472	7.729.152	7.741.440	7.744.512	7.741.440	7.959.552	7.843.840
sectorsize	512	512	512	512	512	512	512	512

Card	microSDHC 8GB SanDisk	microSDHC 8GB Transcend	SDHC 8GB Reekin	SDHC 8GB green memory	SDHC 16GB Panasonic	SDHC 16GB Transcend	SDHC 16GB takeMS	SDHC 16GB PNY
MID-OID	03-4453	1E-4241	1D-4441	27-4850	01-4150	1E-4241	19-5944	02-4D54
maxclk	25MHz	25(50)MHz	25(?)MHz	25(50)MHz	25(50)MHz	25(50)MHz	25(50)MHz	25(50)MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	100.000	100.000	100.000	100.000	100.000	100.000	100.000	100.000
Nbs	250.000	250.000	250.000	250.000	250.000	250.000	250.000	250.000
maxsectors	15.954.944	15.661.056	15.332.352	15.720.448	31.645.696	31.387.648	31.776.768	31.116.288
sectorsize	512	512	512	512	512	512	512	512

Card	microSDHC 16GB SanDisk	SDHC 32GB green memory	microSDHC 32GB SanDisk / ADATA	microSDHC 32GB Samsung	SDXC 64GB Transcend	microSDXC 64GB SanDisk / Team	SDXC 128GB Komputer Bay	microSDXC 128GB SanDisk
MID-OID	03-4453	02-4D54	03-4453	1B-4D53	1E-4241	03-4453	74-454A	03-4453
maxclk	25MHz	25(50)MHz	25MHz	25(50)MHz	25(50)MHz	25MHz	25(50)MHz	25MHz
usedclk*	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz	8MHz
Nac	100.000	100.000	100.000	100.000	100.000	100.000	100.000	100.000
Nbs	250.000	250.000	250.000	250.000	500.000	500.000	500.000	500.000
maxsectors	31.116.288	63.700.992	62.333.952	61.315.072	124.925.952	124.735.488	251.394.048	249.736.192
sectorsize	512	512	512	512	512	512	512	512

Card	microSDXC 200GB SanDisk	microSDXC 400GB SanDisk	nm-card 128GB UTHAI-J39/ YAOMAISI ?
MID-OID	03-4453	03-4453	FF-0000
maxclk	25MHz	25MHz	50MHz
usedclk*	8MHz	8MHz	8MHz
Nac	100.000	100.000	100.000
Nbs	500.000	500.000	500.000
maxsectors	384.503.808	769.277.952	246.988.800
sectorsize	512	512	512

* * To get comparable values for Nac and Nbs, the parameters are readed using the STR-H711 board,
since the highest possible CLK for SPI (on MMC and SD cards) is there 8MHz.

Board	MMC	MMCplus (HS-MMC)	SDxx	HS-SDxx
ATMega128	7,3728MHz (MCLK/2)
STR-H711	8MHz (MCLK/6)
LPC1114 und LCP1343	19,2MHz	48MHz	24MHz	48MHz
LCP1769	12,5MHz	50MHz	25MHz	50MHz
LPC-H2148	12MHz	24MHz
STM32-H103	18MHz (PCLKx/2)
AT91SAM7xxx	15,9744MHz	47,9232MHz	23,9616MHz	47,9232MHz
AT91SAM3SxA Stick	16(24)MHz	48MHz	24MHz	48MHz
SAMD21..	16(24)MHz	48MHz	24MHz	48MHz

Not supported cards:

The Transcend 4GB MMCplus can not be set into SPI Idle-state (GO_IDLE_STATE) (card 394426 01 03)

A lock into a card? Why not ...

inside Panasonic SD 16MB

inside memoQ SD 4GB

What's so special there?
The write-protect switch has no notifying connection to the inner life. That means, is the adapter / host ignoring the switch, you can (if not write-protect has been set by software) still write.



Why different values of maxsectors at cards with the same storage-size ?
In all MMC- and SD-cards a Wear-Leveling is used, to load the physical pages (max. erase-/writecycles of pages) evenly. To realize this, the user gets access to logical pages and these are recalculated to physical pages (like a table). This administration/table needs also one part of the flash-memory of course (and it's not allowed to use alltimes the same physical pages for this).
To Wear-Leveling there are many patents world-wide and since the takeover of M-Systems through SanDisk is this very centrally (-> licenses). But some few good ideas / alternative solutions are patent-free...

And here still some helpful links to the topic MMC/SD , SDHC and Wear-Leveling:

• 64MB MMC und PIC-Mikrocontroller
• Ulrich Radig (AVR/ARM-Projects)
• How to Use an MMC
• SanDisk - SD physical spec
• SanDisk - SD spec v1.9
• SanDisk - SD spec v2.2
• SanDisk - Application notes
• MMC - System Spec v3.31 (short version)
• MMC - System Spec v4.1 (short version)
• SanDisk - MultiMediaCard Product Manual
• Samsung - Comparison btw. MMC & SD (incl. MMC4.2 & SD2.0)
• About SDHC Memory Card
• Simplified Version of PHYSICAL LAYER SPEC V2.0
• ELM - How to support SDC Ver2 and high capacity cards
• Cardspeed - SD 2.00: SDHC with CSD 2.0
• Samsung - High Density MMC Application Note
• Intel - WearLeveling FTL
• M-Systems - Wear Leveling of TrueFSS
• SanDisk - WhitePaper Wear Leveling
• M-Systems - WhitePaper Increasin Life Expectancy of Flash