Hardware Guide

4 Circuit Design
Copyright © Fibocom Wireless Inc. 52
4.4.7.1 PCM Interface Description
Table 41. PCM interface description
Pin Name
Frequency
Duty Ratio
Coding Format
Operating Mode
PCM_CLK
2.048MHz
50%
16bit Liner mono
Module serves as master,
supporting PCM as slave
PCM_OUT
- -
- -
16bit Liner mono
Module serves as master,
supporting PCM as slave
PCM_IN
- -
- -
16bit Liner mono
Module serves as master,
supporting PCM as slave
PCM_SYNC
8KHz
Short pulse
16bit Liner mono
Module serves as master,
supporting PCM as slave
4.4.7.2 PCM Signal Description
The main chip of the module uses PCM signals that comply with the European E1
standard. PCM_CLK works at 2.048 MHz and uses 16-bit linear coding format. PCM_SYNC
is a short pulse of 8 kHz (488 nS).
Figure 20. PCM_SYNC timing sequence