N720 OpenLinux
Hardware User Guide
Copyright © Neoway Technology Co., Ltd
32
SD is a dual-voltage SD3.0 interface, which supports a read rate up to 100MBps and ordinary SD card.
Table 3-3 SD card feature parameters
Mode
IO Level (V)
Max Clock Frequency (MHz)
Timing Mode
SDR
1.8/2.85
200
DS, HS, SDR12, SDR25, SDR50,
SDR104
DDR
50
DDR50
Figure 3-21 shows SD connection.
Figure 3-21 SD connection
SDC_CLK
SDC_CMD
SDC_DATA0
SDC_DATA1
N720 module
SD
connector
SDC_DATA2
SDC_DATA3
SDC_DET
SDC_PWR_EN
VCC
CLK
CMD
DATA0
DATA1
DATA2
DATA3
DET
VDD_SDC_IO
VDD_1P8
10k
Ω
47k
Ω
SDC
Power
10k
Ω
10k
Ω
10k
Ω
10k
Ω
R1
R2
R3
R4
R5
R7
C1
C2
1uF 0.1uF
ESD1
ESD2
4
5
1 2 3
4
5
1 2 3
20
Ω
R6
Schematic Design Recommendations
Note that the logic level of SD interface does not match 3.3V.
VDD_SDC_IO is the power supply to which the DATA and AMD signals of SDC connect through
a pull-up resistor. The power source is determined by the IO level of SD chipset. If the IO level is