C8051F850-C-GM Datasheet, PDF (29/328 Pages) Silicon Laboratories – Low-Cost 8-bit MCU Family with up to 8 kB of Flash

2.3. Clocking
The C8051F85x/86x devices have two internal oscillators and the option to use an external CMOS input at
a pin 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 C8051F85x/86x 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 (center or 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.
Can accept hardware “kill” signal from comparator 0.
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 pin or LFO clock capture capabilities.
2.4.3. Watchdog Timer (WDT0)
The watchdog timer includes a 16-bit timer with a programmable reset period. The registers are protected
from inadvertent access by an independent lock and key interface.
The Watchdog Timer has the following features:
Programmable timeout interval.
Runs from the low frequency oscillator.
Lock-out feature to prevent any modification until a system reset.
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