MEIG SLM770A - PCM (SLM770 A-SC Does Not Support this Function)

SLM770A Module Hardware Design Manual
MeiG Smart Technology Co., Ltd 77/77
Parameter
Min
Max
Unit
V
IL
-0.3
0.6
V
V
IH
1.2
2.0
V
V
OL
0
0.45
V
V
OH
1.35
1.8
V
The serial port level of SLM770A module is 1.8V. If the client host is 3.3V, the level converter needs to be
added in the serial port application. TI's TXB0104PWR is recommended. The following picture is a
reference design:
VCCB
B1
GND
B2
B4
B3
B6
B7
B5
B8
VCCA
A1
OE
A2
A4
A3
A6
A7
A5
A8
Translator
0.1uF
0.1uF
51K
51K
VDD_EXT
VDD_MCU
RI_MCU
DCD_MCU
CTS_MCU
RTS_MCU
DTR_MCU
TXD_MCU
RXD_MCU
RI
DCD
CTS
RTS
DTR
TXD
RXD
Figure 17 Level conversion chip reference circuit
Note:
1. Triode level conversion circuits should not be used for baud rate applications exceeding 460kbps.
2. Hardware flow control is disabled by default. If required, send at+ifc=2
3.12 PCM (SLM770A-SC does not support this function)
The module provides one PCM interface that supports the short frame mode: The module can be used
as either the master device or the slave device.
In short frame mode, data is sampled along the falling edge of PCM_CLK and sent along the rising edge.
The falling edge of PCM_SYNC indicates the high significant bit. The PCM interface supports 256kHz,
512 kHz, 1024 kHz and 2048 kHz PCM_CLK at 8kHz PCM_SYNC, as well as 16 kHz