Sd Card Interface Description; General Description Of Pins And Registers; Pin Assignments In Sd Card Mode - SanDisk SDSDB-32-201-80 - Industrial Grade Flash Memory Card Product Manual

3. SD Card Interface Description

3.1. General Description of Pins and Registers

The SD Card has nine exposed contacts on one side (see Figure 3-1). The host is connected to the SD Card using a
dedicated 9-pin connector.

3.1.1. Pin Assignments in SD Card Mode

Table 3-1 lists the pin assignments and definitions in SD Card Mode.
NOTES: 1) S=power supply; I=input; O=output using push-pull drivers.
2) The extended DAT lines (DAT1-DAT3) are input on power up. They start to operate as DAT lines after the
SET_BUS_WIDTH command. It is the responsibility of the host designer to connect external pullup resistors to all
data lines even if only DAT0 is to be used. Otherwise, non-expected high current consumption may occur due to the
floating inputs of DAT1 & DAT2 (in case they are not used).
3) After power up, this line is input with 50Kohm(+/-20Kohm) pull-up (can be used for card detection or SPI mode
selection). The pull-up may be disconnected by the user, during regular data transfer, with
SET_CLR_CARD_DETECT (ACMD42) command.
SanDisk Secure Digital (SD) Card Product Manual, Rev. 1.9 © 2003 SANDISK CORPORATION
Table 3-1. SD Bus Mode Pad Definition
Pin # Name
1 CD/DAT3
2
2 CMD
3 V
SS1
4 V
DD
5 CLK
6 V
SS2
7 DAT0
8 DAT1
9 DAT2
Type 1 SD Description
I/O Card Detect/Data Line [Bit 3]
3
I/O Command/Response
S Supply voltage ground
S Supply voltage
I Clock
S Supply voltage ground
I/O Data Line [Bit 0]
I/O Data Line [Bit 1]
I/O Data Line [Bit 2]
3-1