User's Manual Part 1
There are 4 configuration pins on the M.2 module to assist the host identifying the presence
of an Add-In card in the socket.
On the M.2 module, pins CONFIG_0..3 are configured as shown in Table 20.
All configuration pins can be read and decoded by the host platform to recognize the
indicated module configuration and host interface supported. On the host side, each of the
CONFIG_0..3 signals needs to be fitted with a pull-up resistor.
Table 20
M.2 Configuration Pins
Signal Name Description Pin Direction
(WWAN)
Voltage
Level
CONFIG_0 This signal is not connected to the WWAN M.2
module.
21
O -
CONFIG_1 Tied to Ground internally on the WWAN M.2
module.
69
O 0 V
CONFIG_2 Tied to Ground internally on the WWAN M.2
module.
75
O 0 V
CONFIG_3 Tied to Ground internally on the WWAN M.2
module.
1
O 0 V
There are 4 signals on the host interface that are reserved to support a digital audio interface.
This is for future development, all existing WWAN M.2 modules do not support audio;
therefore, these signals should be left unconnected at the host to avoid any contention.
Table 21
Audio Signals (Future development)
Signal Name Description Pin Direction
(WWAN)
Voltage
Level
AUDIO0 PCM Clock (I2S_CLK) 20 IO 1.8 V
AUDIO1 PCM In (I2S_RX) 22 I 1.8 V