P89LPC9103 datasheet(35/61 Pages) NXP

35 / 61 page

P89LPC9102_9103_9107_3

Product data sheet

Rev. 03 — 10 July 2007

35 of 61

NXP Semiconductors

P89LPC9102/9103/9107

8-bit microcontrollers with two-clock accelerated 80C51 core

• Power-on detect

• Brownout detect

• Watchdog timer

• Software reset

• UART break character detect reset (P89LPC9103/9107).

For every reset source, there is a ﬂag in the Reset Register, RSTSRC. The user can read

this register to determine the most recent reset source. These ﬂag bits can be cleared in

software by writing a logic 0 to the corresponding bit. More than one ﬂag bit may be set:

• During a power-on reset, both POF and BOF are set but the other ﬂag bits are

cleared.

• For any other reset, previously set ﬂag bits that have not been cleared will remain set.

8.16 Timers 0 and 1

The P89LPC9102 has two general purpose timer/counters which are similar to the

standard 80C51 Timer 0 and Timer 1. These timers have ﬁve operating modes (modes 0,

1, 2, 3, and 6). Modes 0, 1, and 2 are the same for both Timers. Mode 3 is different.

The P89LPC9103/9107 has two general purpose timers which are similar to the standard

80C51 Timer 0 and Timer 1. These timers have four operating modes (modes 0, 1, 2, and

3). Modes 0, 1, and 2 are the same for both Timers. Mode 3 is different.

8.16.1 Mode 0

Putting either Timer into Mode 0 makes it look like an 8048 Timer, which is an 8-bit

Counter with a divide-by-32 prescaler. In this mode, the Timer register is conﬁgured as a

13-bit register. Mode 0 operation is the same for Timer 0 and Timer 1.

8.16.2 Mode 1

Mode 1 is the same as Mode 0, except that all 16 bits of the timer register are used.

8.16.3 Mode 2

Mode 2 conﬁgures the Timer register as an 8-bit counter with automatic reload. Mode 2

operation is the same for Timer 0 and Timer 1.

8.16.4 Mode 3

When Timer 1 is in Mode 3 it is stopped. Timer 0 in Mode 3 forms two separate 8-bit

counters and is provided for applications that require an extra 8-bit timer. When Timer 1 is

in Mode 3 it can still be used by the serial port as a baud rate generator.

8.16.5 Mode 6 (P89LPC9102/9107)

In this mode, the corresponding timer can be changed to a PWM with a full period of

256 timer clocks.

P89LPC9103 Datasheet(PDF) 35 Page - NXP Semiconductors