User's Manual

Smart Machine Smart Decision
SIM5320_Hardware Design_V1.01 2011-11-10
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3.6.1 Application Guide
Currently SIM5320AD supports the USB suspend and resume mechanism which can help to save power.
If no transaction is on USB bus, SIM5320AD will enter suspend mode. When some events such as voice
call or receiving SMS happen, SIM5320AD will resume normal mode automatically.
Figure 24: USB interface
Because of high bit rate on USB bus, pay attention to influence of junction capacitance of ESD component
on USB data lines. Typically, the capacitance should be less than 4pF @1MHz.
Note
： The SIM5320AD has two kinds of interface (UART and USB) to connect to host CPU. USB interface is mapped
to five virtual ports: “SIMTECH USB Modem”, “SIMTECH NMEA Device”, “SIMTECH ATCOM Device”,
“SIMTECH Diagnostics interface” and “SIMTECH Wireless Ethernet Adapter”.
3.7 SPI Interface
SPI interface of SIM5320AD is master only. It provides a duplex, synchronous, serial communication link
with peripheral devices. Its operation voltage is 1.8V, with clock rates up to 26 MHz.
3.7.1 Pin Description
Table 14: Electronic characteristic
1.8V mode
Pin name
Min Typ Max
SPI_CLK 1.65 1.8 1.95
SPI_CS_N 1.65 1.8 1.95