C8051F360 datasheet(247/288 Pages) SILABS

247 / 288 page

Rev. 1.0

247

C8051F360/1/2/3/4/5/6/7/8/9

21. Timers

Each MCU includes four counter/timers: two are 16-bit counter/timers compatible with those found in the

standard 8051, and two are 16-bit auto-reload timer for use with the ADC, SMBus, or for general purpose

use. These timers can be used to measure time intervals, count external events and generate periodic

interrupt requests. Timer 0 and Timer 1 are nearly identical and have four primary modes of operation.

Timer 2 and Timer 3 offer 16-bit and split 8-bit timer functionality with auto-reload.

Timers 0 and 1 may be clocked by one of five sources, determined by the Timer Mode Select bits (T1M–

T0M) and the Clock Scale bits (SCA1–SCA0). The Clock Scale bits define a pre-scaled clock from which

Timer 0 and/or Timer 1 may be clocked (See SFR Definition 21.3 for pre-scaled clock selection).

Timer 0/1 may then be configured to use this pre-scaled clock signal or the system clock. Timer 2 and

Timer 3 may be clocked by the system clock, the system clock divided by 12, or the external oscillator

clock source divided by 8.

Timer 0 and Timer 1 may also be operated as counters. When functioning as a counter, a counter/timer

quency of up to one-fourth the system clock frequency can be counted. The input signal need not be peri-

odic, but it should be held at a given level for at least two full system clock cycles to ensure the level is

properly sampled.

Timer 0 and Timer 1 Modes:

Timer 2 Modes:

Timer 3 Modes:

13-bit counter/timer

16-bit timer with auto-reload

16-bit counter/timer

8-bit counter/timer with auto-

reload

Two 8-bit timers with auto-reload

Two 8-bit counter/timers (Timer 0

only)

C8051F360 Datasheet(PDF) 247 Page - Silicon Laboratories