P89LPC932A1FA NXP Semiconductors, P89LPC932A1FA Datasheet - Page 38

• 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
Fig 20. Comparator input and output connections
(P0.5) CMPREF
7.23.1 Internal reference voltage
7.23.2 Comparator interrupt
(P0.4) CIN1A
(P0.3) CIN1B
(P0.2) CIN2A
(P0.1) CIN2B
7.23 Analog comparators
V
ref(bg)
Two analog comparators are provided on the P89LPC932A1. Input and output options
allow use of the comparators in a number of different configurations. Comparator
operation is such that the output is a logic 1 (which may be read in a register and/or routed
to a pin) when the positive input (one of two selectable pins) is greater than the negative
input (selectable from a pin or an internal reference voltage). Otherwise the output is a
zero. Each comparator may be configured to cause an interrupt when the output value
changes.
The overall connections to both comparators are shown in
function to V
When each comparator is first enabled, the comparator output and interrupt flag are not
guaranteed to be stable for 10 microseconds. The corresponding comparator interrupt
should not be enabled during that time, and the comparator interrupt flag must be cleared
before the interrupt is enabled in order to prevent an immediate interrupt service.
An internal reference voltage generator may supply a default reference when a single
comparator input pin is used. The value of the internal reference voltage, referred to as
V
Each comparator has an interrupt flag contained in its configuration register. This flag is
set whenever the comparator output changes state. The flag may be polled by software or
may be used to generate an interrupt. The two comparators use one common interrupt
vector. If both comparators enable interrupts, after entering the interrupt service routine,
the user needs to read the flags to determine which comparator caused the interrupt.
REF
, is 1.23 V
DD
CP1
CN1
CP2
CN2
= 2.4 V.
10 %.
comparator 1
comparator 2
Rev. 03 — 12 March 2007
8-bit microcontroller with accelerated two-clock 80C51 core
CO1
CO2
change detect
change detect
OE1
OE2
CMF1
CMF2
CMP1 (P0.6)
CMP2 (P0.0)
Figure
P89LPC932A1
002aaa904
EC
20. The comparators
© NXP B.V. 2007. All rights reserved.
interrupt
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