P89LPC9201 Datasheet, PDF (36/74 Pages) NXP Semiconductors – 8-bit microcontroller with accelerated two-clock 80C51 core 2 kB/4 kB/8 kB 3 V byte-erasable flash with 8-bit ADC

NXP Semiconductors
P89LPC9201/9211/922A1/9241/9251
8-bit microcontroller with 8-bit ADC
7.19.1 Reset vector
Following reset, the P89LPC9201/9211/922A1/9241/9251 will fetch instructions from
either address 0000H or the Boot address. The Boot address is formed by using the boot
vector as the high byte of the address and the low byte of the address = 00H.
The boot address will be used if a UART break reset occurs, or the non-volatile boot
status bit (BOOTSTAT.0) = 1, or the device is forced into ISP mode during power-on (see
P89LPC9201/9211/922A1/9241/9251 User manual). Otherwise, instructions will be
fetched from address 0000H.
7.20 Timers/counters 0 and 1
The P89LPC9201/9211/922A1/9241/9251 has two general purpose counter/timers which
are upward compatible with the standard 80C51 Timer 0 and Timer 1. Both can be
configured to operate either as timers or event counters. An option to automatically toggle
the T0 and/or T1 pins upon timer overflow has been added.
In the ‘Timer’ function, the register is incremented every machine cycle.
In the ‘Counter’ function, the register is incremented in response to a 1-to-0 transition at its
corresponding external input pin, T0 or T1. In this function, the external input is sampled
once during every machine cycle.
Timer 0 and Timer 1 have five operating modes (Modes 0, 1, 2, 3 and 6). Modes 0, 1, 2
and 6 are the same for both Timers/Counters. Mode 3 is different.
7.20.1 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.
7.20.2 Mode 1
Mode 1 is the same as Mode 0, except that all 16 bits of the timer register are used.
7.20.3 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.
7.20.4 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.
7.20.5 Mode 6
In this mode, the corresponding timer can be changed to a PWM with a full period of
256 timer clocks.
P89LPC92X1_1
Preliminary data sheet
Rev. 01 — 16 April 2009
© NXP B.V. 2009. All rights reserved.
36 of 74