SimCom SIM5320AL, Руководство пользователя

Страница: 44 / 67

Smart Machine Smart Decision
SIM5320AL_User Manual_V1.01 2014-08-20 44
Table 26: Control status
GPIO4 Status Module operation
Low Level Flight Mode: RF is closed.
High Level Normal Mode: RF is working.
Note
：
1. When the module is powered off, make sure all digital interfaces (UART, etc) connected with peripheral devices have
no voltage higher than 0.3V. If users’ design cannot meet above conditions, high level voltages maybe occur in GPIO
pins because current leakage from above digital interfaces may occur.
3.11 PCM Interface
SIM5320 provides hardware PCM interface for external codec. The PCM interface enables
communication with an external codec to support hands-free applications. SIM5320 PCM interface can be
used in two modes: the default mode is auxiliary PCM (8 KHz long sync mode at 128 KHz PCM CLK);
the other mode is primary PCM (8 KHz short sync mode at 2048 KHz PCM CLK). In short-sync
(primary PCM) mode, SIM5320 can be a master or a slave. In long-sync (auxiliary PCM) mode, SIM5320
is always a master. SIM5320 also supports 3 kinds of coding formats: 8 bits (

-law or A-law) and 16 bits
(linear).
Note: PCM interface is multiplexed from GPIO (default setting). The AT command “AT+CPCM” is used to switch
between PCM and GPIO functions. Please refer to document [22] and document [1] for details.
3.11.1 Pin Description
Table 27: Electronic characteristic
Pin name
DC Characteristics
Min Typ Max
PCM_CLK -0.3 2.6 2.9
PCM_SYNC -0.3 2.6 2.9
PCM_DOUT -0.3 2.6 2.9
PCM_DIN -0.3 2.6 2.9
Table 28: Pin description
Pins Pin No.
AUX_PCM
functionality Primary PCM
functionality
Description