Product manual

3. Industrial Grade SD Card Interface Description

3.1. General Description of Pins and Registers

The Industrial Grade 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 Industrial Grade SD Card Mode

Table 3-1 lists the pin assignments and definitions in SD Card Mode.

Table 3-1. SD Bus Mode Pad Definition

Pin # Name Type

SD Description

1 CD/DAT3

I/O

Card Detect/Data Line [Bit 3]

2 CMD I/O Command/Response

3 V

SS1

S Supply voltage ground

4 V

S Supply voltage

5 CLK I Clock

6 V

SS2

S Supply voltage ground

7 DAT0 I/O Data Line [Bit 0]

8 DAT1 I/O Data Line [Bit 1]

9 DAT2 I/O Data Line [Bit 2]

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.