Figure 20. CONN_SD_CARD 8

9.1 Software—Micro SD Card

SD.h file

The SD Card communication is a command protocol, these commands are declared at the SD.h file. Functions are located in

the SD.c file. The following commands are the principal commands.

Table 6. SD Card Command

Description

Command

Resets the SD memory card

SD_CMD0

Initialization process

SD_CMD1

Check mode 0 and mode 1

SD_CMD6

Host supply voltage

SD_CMD8

CSD

SD_CMD9

CID

SD_CMD10

Stop transmission

SD_CMD12

Sends status register

SD_CMD13

Sets a block length

SD_CMD16

Reads a block

SD_CMD17

Continuously transfers

SD_CMD18

Writes a block

SD_CMD24

Continuously writes up to Stop mode

SD_CMD25

Programs programmable bits of the CSD

SD_CMD27

Sets the write protection bit

SD_CMD28

Clears the write protection

SD_CMD29

Sends the status of the write protection

SD_CMD30

Sets the address of the first write block

SD_CMD32

Sets the address of the last write block

SD_CMD33

Erases all previously selected write blocks

SD_CMD38

Used to Set or Reset the password or lock and unlock the card

SD_CMD42

Implementing a Glucometer and Blood Pressure Monitor Medical Devices, Rev. 1, 4/2010

21

Freescale Semiconductor, Inc.

Micro SD Card