At first we need to understand SIM Pinouts:
| Contact No | Assignment | Description |
|---|---|---|
| C1 | VCC | Power Voltage. |
| C2 | RST | Reset Signal. |
| C3 | CLK | Clocking Signal. |
| C4 | RFU | Reserved for Feature Use. |
| C5 | GND | Power and Signal Ground. |
| C6 | VPP | Programming Voltage. |
| C7 | I/O | Serial Data input/output. |
| C8 | RFU | Reserved for Feature Use |