P89LPC932A1FA NXP Semiconductors, P89LPC932A1FA Datasheet - Page 25

• Manufacturer Part Number: P89LPC932A1FA
• Description: MCU 8-Bit 89LP 80C51 CISC 8KB Flash 2.5V/3.3V 28-Pin PLCC Tube
• Manufacturer: NXP Semiconductors

Specifications of P89LPC932A1FA

• Package: 28PLCC
• Device Core: 80C51
• Family Name: 89LP
• Maximum Speed: 18 MHz
• Operating Supply Voltage: 2.5|3.3 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 26
• Interface Type: I2C/SPI/UART
• Number Of Timers: 2
• Ram Size: 768 Byte
• Program Memory Size: 8 KB
• Program Memory Type: Flash
• Operating Temperature: -40 to 85 °C

NXP Semiconductors
P89LPC932A1_3
Product data sheet
7.16.1 Reset vector
7.17.1 Mode 0
7.17 Timers/counters 0 and 1
After power-up this input will function either as an external reset input or as a digital input
as defined by the RPE bit. Only a power-up reset will temporarily override the selection
defined by RPE bit. Other sources of reset will not override the RPE bit.
Reset can be triggered from the following sources:
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:
Following reset, the P89LPC932A1 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
P89LPC932A1 User manual ). Otherwise, instructions will be fetched from address 0000H.
The P89LPC932A1 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 counter. 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.
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.
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External reset pin (during power-up or if user configured via UCFG1).
Power-on detect.
Brownout detect.
Watchdog timer.
Software reset.
UART break character detect reset.
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.
Rev. 03 — 12 March 2007
8-bit microcontroller with accelerated two-clock 80C51 core
P89LPC932A1
© NXP B.V. 2007. All rights reserved.
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