• The PWRGD output ensures that the ATWILC3000 wireless module is kept in reset until its power rails are
stable.
Figure 3-47. Wi-Fi/Bluetooth Enable Schematic
5V_MAIN
VIN
1
VIN
2
SHDN
3
GND 4
PWRGD
5
CDELAY 6
SENSE 7
VOUT 8
EP 9
MCP1725/3.3V
U19
2.2uF
16V
0603
C215
2.2uF
16V
0603
C216
1000pF
25V
0402
C217
WILC3000_ENABLE
VDD_3V3_WILC
WILC3000_EN_PE0
Note:
When the ATWILC3000 module is enabled, the Flexcom SPI cannot be used with the RPi 40-pin connector.
3.4.10
Secure Digital Multimedia Card
The SD (Secure Digital) Card is a non-volatile memory card format used as a mass storage memory in mobile
devices.
The SAMA7G54-EK has one Secure Digital Multimedia Card (SDMMC) interface that supports the MultiMedia
Card (e.MMC) specification V4.51, the SD Memory Card specification V3.0, and the SDIO V3.0 specification. It is
compliant with the SD Host Controller Standard V3.0 specification.
A standard MMC/SD Card connector, connected to the SDMMC interface, is mounted on the top side of the board.
The SDMMC0 communication is based on an 8-pin interface (clock, command, four data and power lines). It includes
a card detection switch.
Figure 3-48. SD Card Interface Schematic
SD CARD INTERFACE
10uF
25V
0603
C129
10k
0402
1%
R115
SD
DAT3
1
CMD
2
VSS1
3
VDD
4
CLK
5
VSS2
6
DAT0
7
DAT1
8
DAT2
9
CD
10
WP
11
SHIELD
12
J4
47k
0402
5%
R112
47k
0402
5%
R113
47k
0402
5%
R114
10k
0402
1%
R111
i
SDCARD
Matched Net Lengths [Tolerance = 0.25mm]
GND
GND
SDMMC1_CMD_PB29
SDMMC1_CK_PB30
SDMMC1_DAT1_PC0
SDMMC1_DAT2_PC1
SDMMC1_CD_PC4
47k
0402
5%
R110
0.1uF
10V
0402
C126
SDMMC1_DAT3_PC2
SDMMC1_DAT0_PB31
SDMMC1_WP_PC3
10k
0402
1%
R116
VDDSDMMC1
VDD_3V3
50
Ω
± 10% single-ended trace impedance
VDD_SDCARD
The table below describes the pin assignment of SD/MMC connector J4.
Table 3-39. Standard SD Socket J4 Pin Assignment Signal Descriptions
Function
Pin
PIO
Signal Description
SD Card data line 3
1
PC2
SDMMC1_DAT3_PC2
SD Card command line
2
PB29
SDMMC1_CMD_PB29
Ground
3
–
Ground
SAMA7G54-EK
Function Blocks
©
2022 Microchip Technology Inc.
and its subsidiaries
User Guide
DS50003273A-page 56
