Datasheet

Figure 5-2. Contact Area
- 15 -
datasheet SD Card
Rev. 1.0
MMBTFxxGWBCA-xMExx
5.3.2 microSD Card Assignment
[Table 5-2] : microSD Contact Pad Assignment
NOTE:
1) S: power supply; I: input; O: output using push-pull drivers; PP: I/O using push-pull drivers ;
2) The extended DAT lines (DAT1-DAT3) are input on power up. They start to operate as DAT lines after
SET_BUS_WIDTH command. The Host shall keep its own DAT1-DAT3 lines in input mode, as well,
while they are not used.
3) At power up this line has a 50KOhm pull up enabled in the card. This resistor serves two functions Card
detection and Mode Selection. For Mode Selection, the host can drive the line high or let it be pulled
high to select SD mode. If the host wants to select SPI mode it should drive the line low. For Card
detection, the host detects that the line is pulled high. This pull-up should be disconnected by the user,
during regular data transfer, with SET_CLR_CARD_DETECT (ACMD42)
4) DAT1 line may be used as Interrupt Output (from the Card) in SDIO mode during all the times that it
is not in use for data transfer operations (refer to "SDIO Card Specification" for further details).
5) DAT2 line may be used as Read Wait signal in SDIO mode (refer to "SDIO Card Specification" for further details).
Pin #
SD Mode SPI Mode
Name
Type
1
Description Name
Type
1
Description
1
DAT2
2.5
I/O/PP Data Line [Bit 2] RSV Reserved
2
CD/DAT3
2
I/O/PP
3
Card Detect /
Data Line [Bit 3]
CS
I
3
Chip Select (neg true)
3 CMD PP Command/Response DI I Data In
4V
DD S Supply voltage VDD S Supply voltage
5 CLK I Clock SCLK I Clock
6V
SS S Supply voltage ground VSS S Supply voltage ground
7 DAT0 I/O/PP Data Line [Bit 0] DO O/PP Data Out
8
DAT1
2.4
I/O/PP Data Line [Bit 1]
RSV
4
Pin 1 Pin 2 Pin 3 Pin 5 Pin 4 Pin 6 Pin 7 Pin 8