Pi 2 Design CM4AES Hardware Reference Manual – P0.1
PAGE 11
use the SDIO port as the storage.
5.3
COMPUTE MODULE 4 GPIO
The CM4 provides a large number of General Purpose I/O (GPIO) pins. These pins also
can be assigned to alternate functions as defined in the CM4 documentation. The usage
of these pins (and alternate functions) on the CM4AES are described in the following
table.
GPIO DIR
AF
PUP
PDN
CM4AES
Usage
Description/Notes
0
I/O
I2C0
PUP
SDA0
Routed to P5 for DSI 0
1
I/O
I2C0
PUP
SCL0
Routed to P5 for DSI 0
2
I/O
I2C1
PUP
SDA
I2C Data for CM4AES and Expansion
3
I/O
I2C1
PUP
SCL
I2C Clock for CM4AES and Expansion
4
I/O
GPIO4
Routed to P1 Expansion Connector
5
I/O
GPIO5
Routed to P1 Expansion Connector
6
I/O
GPIO6
WM8804 Master Clock Select
7
-
unused
8
-
unused
9
-
unused
10
-
unused
11
-
unused
12
-
unused
13
-
unused
14
OUT UART1
TXD
Routed to P3 Header
15
IN
UART1
RXD
Routed to P3 Header
16
-
unused
17
-
unused
18
IN
I2S
BCLK
I2S Bit Clock from WM8804
19
IN
I2S
WCLK
I2S Word Clock from WM8804
20
-
unused
