User's Manual

Smart Machine Smart Decision

SIM7100A_User Manual_V1.01 2014-12-11

3.4.1 USB Application Guide

Normally, SIM7100A is a USB device. SIM7100A supports the USB suspend and resume mechanism

which can help to save power. If no transaction is on USB bus, SIM7100A will enter suspend mode.

When some events such as voice call or receiving SMS happen, SIM7100A will resume normal mode

automatically.

SIM7100A is a USB host controller.

Figure 18: USB Reference Circuit with SIM7100A as USB Host Controller.

Because of high bit rate on USB bus, please pay attention to influence of junction capacitance of ESD

component on USB data lines. Typically, the capacitance should be less than 1pF ,It is recommended to

use an ESD protection component such as ON SEMI (www.onsemi.com ) ESD9L5.0ST5G.

Note

：

The SIM7100A has two kinds of interface (UART and USB) to connect to host CPU. USB

interface is mapped to five virtual ports: “SIMTECH HS-USB Modem 9001”, “SIMTECH HS-USB

NMEA 9001”, “SIMTECH HS-USB AT port 9001”, “SIMTECH HS-USB Diagnostics 9001” and

“SIMTECH Wireless HS-USB Ethernet Adapter 9001”.