AT89LP428 datasheet(50/149 Pages) ATMEL

номер детали	AT89LP428

подробное описание детали	8-bit Microcontroller with 4K/8K Bytes In-System Programmable Flash

PDF	149 Pages

Scroll/Zoom	100%

производитель	ATMEL [ATMEL Corporation]

домашняя страница	http://www.atmel.com

Logo

50 / 149 page

3654A–MICRO–8/09

AT89LP428/828

Figure 11-9. PWM Mode 2 Waveform

11.5.4

Mode 3 – Split 8-bit PWM

Timer 1 in PWM mode 3 simply holds its count. The effect is the same as setting TR1 = 0.

Timer 0 in PWM mode 3 establishes TL0 and TH0 as two separate PWM counters in a manner

similar to normal mode 3. PWM mode 3 on Timer 0 is shown in Figure 11-10. Only the Timer

Prescaler is available to change the output frequency during PWM mode 3. TL0 can use the

Timer 0 control bits: GATE, TR0, INT0, PWM0EN and TF0. TH0 is locked into a timer function

and uses TR1, PWM1EN and TF1. RL0 provides the duty cycle for TL0 and RH0 provides the

duty cycle for TH0.

PWM mode 3 is for applications requiring a single PWM channel and two timers, or two PWM

channels and an extra timer or counter. With Timer 0 in PWM mode 3, the AT89LP428/828 can

appear to have three Timer/Counters. When Timer 0 is in PWM mode 3, Timer 1 can be turned

on and off by switching it out of and into its own mode 3. In this case, Timer 1 can still be used by

the serial port as a baud rate generator or in any application not requiring an interrupt. The fol-

lowing formulas give the output frequency and duty cycle for Timer 0 in PWM mode 3.

THx

FFh

Mode 3:

fOUT

Oscillator Frequency

256

-------------------------------------------------------

TPS

---------------------

Mode 3, T0:

Duty Cycle %

100

RL0

256

-----------

Mode 3, T1:

Duty Cycle %

100

RH0

256

------------

AT89LP428 датащи(PDF) 50 Page - ATMEL Corporation