3.3.5.2.2 AVR SPI Pinout
For a legacy application PCB which includes an AVR with the SPI interface, the pinout as shown in the figure below may have been used.
| MPLAB PICkit Basic Pin | Adapter Board AVR JTAG Pin | Legacy SPI Pin | Name | Description | 
|---|---|---|---|---|
| 1 | 7 or 8 (NC) | |||
| 2 | 4 (VDD/VTG) | 2 | VCC/VTG | Target voltage (reference voltage) | 
| 3 | 2 or 10 (GND) | 6 | GND | Ground | 
| 4 | 3 (TDO) | 1 | MISO | Host In Client Out (Main In Secondary Out) | 
| 5 | 1 (TCK) | 3 | SCK | SPI clock | 
| 6 | 6 (RESET/TAUX) | 5 | RESET | |
| 7 | 9 (TDI) | 4 | MOSI | Host Out Client In (Main Out Secondary In) | 
| 8 | 5 (TMS) | 
