beautypg.com

Timers 0 and 1 – Philips P89LPC903 User Manual

Page 49

background image

Philips Semiconductors

User’s Manual - Preliminary -

P89LPC901/902/903

TIMERS 0 AND 1

2003 Dec 8

49

Figure 5-7: Timer/Counter 0 Mode 3 (two 8-bit counters)

Figure 5-8: Timer/Counter 0 in Mode 6 (PWM auto-reload), P89LPC901.

Timer Overflow toggle output - P89LPC901

Timer 0 can be configured to automatically toggle the T0 pin whenever the timer overflow occurs. This function is enabled by
control bit ENT0 in the AUXR1 register. The port output will be a logic 1 prior to the first timer overflow when this mode is turned
on. In order for this mode to function, the T0C/T bit must be cleared selecting PCLK as the clock source for the timer.

TL0

(8-bits)

TR0

T0 Pin*

C/T = 0

C/T = 1

Interrupt

T0 Pin*

Control

Toggle

ENT0

TF0

PCLK

Overflow

TH0

(8-bits)

Interrupt

Control

TF1

Overflow

TR1

PCLK

* T0 Pin functions available on P89LPC901

TL0

(8-bits)

TR0

T0C/T = 0

TH0

(8-bits)

Interrupt

T0 Pin

Control

Toggle

ENT0 (AUXR1.4)

TF0

PCLK

Reload TH0 on falling transition

Overflow

and (256-TH0) on rising transition

This manual is related to the following products: