ADC1 conversions are controlled by the START pin or by serial commands. If using commands to control ADC1 conversions, keep the START pin low to avoid possible contentions between the START pin and commands.
ADC1 has two conversion modes: continuous or pulse. Continuous-conversion mode converts indefinitely until stopped by the user. Pulse-conversion mode performs one conversion after the START pin is taken high or after the start command is sent. Use RUNMODE (bit 6, MODE0) to program the conversion mode. Figure 9-38 shows the start and stop timing to control ADC conversions.
|tw(STH)||START pin high: pulse duration||4||tCLK(1)|
|tw(STL)||START pin low to re-start conversion: pulse duration||4||tCLK|
|td(STDR)||Start condition to DRDY high: delay time||Pulse conversion mode||2||tCLK|
|tsu(STDR)||Stop condition to DRDY↓ stopping additional conversions: set-up time||Continuous conversion mode||16||tCLK|
|th(DRSP)||DRDY↓ to stop condition to continue current conversion: hold time||Continuous conversion mode||16||tCLK|