6.2 Inter-Die signal description
| Signal Name | Function | Type | Signal is connected to |
|---|---|---|---|
| DIG3 |
1. RX/TX Indication 2. If disabled, pull-down enabled (AVSS) | Digital output | RFCTRL |
| DIG4 |
1. RX/TX Indication (DIG3 inverted) 2. If disabled, pull-down enabled (AVSS) | Digital output | RFCTRL |
| /RST | Chip reset; active low | Digital input | L21 PB15 |
| DIG1 |
1. Antenna Diversity RF switch control 2. If disabled, pull-down enabled (DVSS) | Digital output | RFCTRL |
| DIG2 |
1. Antenna Diversity RF switch control (DIG1 inverted) 2. RX Frame Time Stamping 3. If functions disabled, pull-down enabled (DVSS) | Digital output | RFCTRL |
| SLP_TR | Controls sleep, transmit start, and receive states; active high | Digital input | L21 PA20 |
| CLKM | Master clock signal output; low if disabled | Digital output | L21 PC16 |
| SCLK | SPI clock | Digital input | L21 PC18 |
| MISO | SPI data output (master input slave output) | Digital output | L21 PC19 |
| MOSI | SPI data input (master output slave input) | Digital input | L21 PB30 |
| /SEL | SPI select, active low | Digital input | L21 PB31 |
| IRQ |
1. Interrupt request signal; active high or active low; configurable 2. Frame Buffer Empty Indicator; active high | Digital output | L21 PB00 |