2.3. Clocking
The C8051F97x devices have three internal oscillators and the option to use an external crystal, RC, C, or CMOS
oscillator as the system clock. A programmable divider allows the user to internally run the system clock at a
slower rate than the selected oscillator if desired.
2.4. Counters/Timers and PWM
2.4.1. Programmable Counter Array (PCA0)
The C8051F97x devices include a three-channel, 16-bit Programmable Counter Array with the following features:
16-bit time base.
Programmable clock divisor and clock source selection.
Three independently-configurable channels.
8, 9, 10, 11 and 16-bit PWM modes (edge-aligned operation).
Output polarity control.
Frequency output mode.
Capture on rising, falling or any edge.
Compare function for arbitrary waveform generation.
Software timer (internal compare) mode.
Module 2 acts as a Watchdog Timer.
2.4.2. Timers (Timer 0, Timer 1, Timer 2, and Timer 3)
Timers include the following features:
Timer 0 and Timer 1 are standard 8051 timers, supporting backwards-compatibility with firmware and
hardware.
Timer 2 and Timer 3 can each operate as 16-bit auto-reload or two independent 8-bit auto-reload timers,
and include Comparator 0 or SmaRTClock clock capture capabilities.
27
Rev 1.1