This note presents how to use the ST62 Auto-reload Timer (ARTimer) for the generation of a PWM signal tunable in frequency and duty cycle. As example, the generation of a 30kHz PWM signal with duty cycle proportional to an analog input voltage is presented.
Auto-reload Timer description
This timer is an 8 bit timer/counter with prescaler. It includes auto-reload PWM, capture and compare capability with one input and one output pins. It is controlled by the following registers (8 bit):
- Mode Control Register (MC)
- Status registers (SC0, SC1)
- Load register (LR)
- Incremental counter register (TC)
- Compare register (CP)
- Reload/Capture register (RC)
It can also wake the MCU from wait mode and exit from stop mode if an external event is present on the
input pin. The prescaler ratio can be programmed to choose the timer input frequency FIN (see Table 1).