5G Module Series
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4 Application Interfaces
The physical connections and signal levels of RG255C-GL Mini PCIe comply with PCI Express Mini Card
Electromechanical Specification. This chapter mainly describes the definition and application of the
following interfaces and pins of RG255C-GL Mini PCIe:
⚫ (U)SIM interface
⚫ USB interface
⚫ UART
⚫ PCM* and I2C interfaces
⚫ Control and indication signals
4.1. (U)SIM Interface
The (U)SIM interface circuitry meets ETSI and IMT-2000 requirements. Either 1.8 V or 3.0 V (U)SIM card
is supported. The following table shows the pin definition of (U)SIM interface.
Table 8: Pin Definition of (U)SIM Interface
RG255C-GL Mini PCIe supports (U)SIM card hot-plug via the USIM_DET pin. The function supports
low-level and high-level detections. Disabled by default, it can be configured via AT+QSIMDET. See
document [3] for details about the command.
The following figure shows a reference design for (U)SIM interface with an 8-pin (U)SIM card connector.