DSB75 Development Support Board Rev. B1 Hardware Description
Confidential / Released
DSB75_hd_v12
Page 50 of 96
2008-08-26
3.10.1
SD 4 Bit Mode
Table 19: Pin assignment of SD card interface X301 (SD 4 bit mode)
X301
pin
X301
signal
name
I/O
Description
Remark
X100
signal
name
Configuration
switches
1
CD/DAT3 I/O
Data line bit 3,
Card detect
Card detect at power on:
0 or open = card removed
1 or 50k pull-up = card
inserted
Note:
This is no removal
detection during card
operation!
SD_D3 S453:1
S301:1
2 CMD O Command
/
Response
SD_CMD
S455:1
S303:1
3 VSS1 Supply
Ground
GND
4 VDD Supply
Supply
voltage
2.9V
5 CLK O Clock
25.4kHz
…13MHz
(depends on SW
performance)
SD_CLK S454:1
S305:1
6 VSS2 Supply
Ground
GND
7
DAT0
I/O
Data line bit 0
SD_D0
S450:1
S307:1
8
DAT1
I/O
Data line bit 1
SD_D1
S451:1
9
DAT2
I/O
Data bus bit 2
SD_D2
S452:1
10 CD
I
Card
detection
0 = card inserted
1 = card removed
Note:
On each edge an
interrupt will be
generated. Removing the
card will stop its operation
before disconnecting it.
SD_DET
11 WP
I
Write
protect
detection
0 = unlocked
1 = locked
SD_WP
