Datasheet

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datasheet SD Card
Rev. 1.0
MMBTFxxGWBCA-xMExx
6.0 SD/MICROSD CARD FUNCTIONAL DESCRIPTION
6.1 General
SEC SD/microSD Card Functional Description contained in this chapter; Section 6.2~6.14; basically, comfort to SDA Physical Layer Specification, Version
3.00. See Chapter 4 of the SDA Physical Layer Specification, Version 3.00 for detail information and guide.
6.2 Card Identification Mode
While in Card Identification mode the host resets all the cards that are in card identification mode, validates operation voltage range, identifies cards and
asks them to publish Relative Card Address(RCA). This operation is done to each card separately on its own CMD line. Refer to Section 4.2 of the SDA
Physical Layer Specification, Version 3.00 for detail information and guide
1)
NOTE :
1) The products on this specification does not support UHS-1 mode. For correct identification flow, please refer to Section 4.2 of the SDA Physical Layer Specification, Version
2.00.
6.3 Clock Control
The SD/microSD Memory Card bus clock signal can be used by the host to change the cards to energy saving mode or to control the data flow(to avoid
under-run or over-run conditions) on the bus. Refer to Section 4.4 of the SDA Physical Layer Specification, Version 3.00 for detail information and guide
6.4 Cyclic Redundancy Code
The CRC is intended for protecting SD Card commands, responses and data transfer against transmission errors on the SD Card bus. One CRC is gen-
erated for every command and checked for every response on the CMD line. For data blocks one CRC per transferred block, per data line, is generated.
The CRC is generated and checked as described in the Section 4.5 of the SDA Physical Layer Specification, Version 3.0
6.5 Command
There are four kinds of commands defined to control the SD Card:
* Broadcast commands (bc), no response - The broadcast feature is only if all the CMD lines are connected together
in the host. If they are separated then each card will accept it separately on his turn.
* Broadcast commands with response (bcr) - response from all cards simultaneously. Since there is no Open Drain
mode in SD Card, this type of command is used only if all the CMD lines are separated. The command will
be accepted and responded to by every card seperately.
* Addressed (point-to-point) commands (ac) - no data transfer on DAT lines
* Addressed (point-to-point) data transfer commands (adtc), data transfer on DAT lines
All commands and responses are sent over the CMD line of the SD Card bus. The command transmission always starts with the left bit of the bitstring cor-
responding to the command code word. For more details, refer to the Section 4.7 of the SDA Physical Layer Specification, Version 3.0.
NOTE:
Limited Vendor CMD information, only for certain customer and application, can be provided under appropriate purpose of usage.