• The SDMMC0 interface is connected to a standard SD card interface.
• The SDMMC1 interface is connected to a WILC3000.
3.4.5.2
SDMMC0 Card Connector (J9)
The board provides a standard MMC/SD card connector, connected to SDMMC0. The SDMMC0 communication is
based on an 8-pin interface (clock, command, write protect, power switch and data (4)). A card detection switch is
included.
The figure below illustrates the SDMMC0 interface implementation.
Figure 3-9. SDMMC0 Schematic
GND
i
SDMMC
Matched Net Lengths [Tolerance = 0.25mm]
68k
0402
5%
R81
4.7uF
10V
0402
C5
DAT3
1
CMD
2
VSS1
3
VDD
4
CLK
5
VSS2
6
DAT0
7
DAT1
8
DAT2
9
CD
10
WP
11
SHIELD
12
SD
J9
GND
VDD_3V3
10k
0402
1%
R84
10k
0402
1%
R83
10k
0402
1%
R76
68k
0402
5%
R80
68k
0402
5%
R79
68k
0402
5%
R78
VDDSDHC
SDMMC0_WP_PA12
SDMMC0_DAT2_PA04
SDMMC0_CMD_PA01
SDMMC0_DAT3_PA05
SDMMC0_CLK_PA00
SDMMC0_DAT0_PA02
SDMMC0_DAT1_PA03
SDMMC0_CD_PA13
10000pF
50V
0402
C23
22R
0402 1%
R75
22R
0402 1%
R94
22R
0402 1%
R96
22R
0402 1%
R157
22R
0402 1%
R158
22R
0402 1%
R159
0.1uF
10V
0402
C4
50Ω ± 10% single-ended trace impedance
Figure 3-10. VDDSDHC Power Switch Schematic
10k
0402
1%
R93
0.1uF
10V
0402
C16
VDD_3V3
GND
GND
GND
VDD_3V3
VDDSDHC
VDD_1V8
SDMMC0_VDDSEL_PA11
IN
1
VDD
2
GND 3
S1
4
D 5
S2
6
ADG849
U5
1uF
10V
0402
C28
IN=0: S1 Closed
IN=1: S2 Closed
ATSAMA5D27-WLSOM1-EK1
Baseboard Components
©
2019 Microchip Technology Inc.
User Guide
DS50002931A-page 13
