p89lpc9171fdh NXP Semiconductors, p89lpc9171fdh Datasheet - Page 46

• Manufacturer Part Number: p89lpc9171fdh
• Description: 8-bit Microcontroller With Accelerated Two-clock 80c51 Core, 2 Kb 3 V Byte-erasable Flash With 8-bit Adc
• Manufacturer: NXP Semiconductors

NXP Semiconductors
P89LPC9151_61_71_2
Product data sheet
7.16.1 Brownout detection
7.16.2 Power-on detection
7.17.1 Idle mode
7.16 Power monitoring functions
7.17 Power reduction modes
Every output on the P89LPC9151/9161/9171 has been designed to sink typical LED drive
current. However, there is a maximum total output current for all ports which must not be
exceeded. Please refer to
All ports pins that can function as an output have slew rate controlled outputs to limit noise
generated by quickly switching output signals. The slew rate is factory-set to
approximately 10 ns rise and fall times.
The P89LPC9151/9161/9171 incorporates power monitoring functions designed to
prevent incorrect operation during initial power-up and power loss or reduction during
operation. This is accomplished with two hardware functions: Power-on detect and
brownout detect.
The brownout detect function determines if the power supply voltage drops below a
certain level. Enhanced brownout detection has 3 independent functions: BOD reset,
BOD interrupt and BOD FLASH.
BOD reset is always on except in total Power-down mode. It could not be disabled in
software. BOD interrupt may be enabled or disabled in software. BOD FLASH is always
on, except in Power-down modes and could not be disabled in software.
BOD reset and BOD interrupt, each has four trip voltage levels. BOE1 bit (UCFG1.5) and
BOE0 bit (UCFG1.3) are used as trip point configuration bits of BOD reset. BOICFG1 bit
and BOICFG0 bit in register BODCFG are used as trip point configuration bits of BOD
interrupt. BOD reset voltage should be lower than BOD interrupt trip point. BOD FLASH is
used for flash programming/erase protection and has only 1 trip voltage of 2.4 V. Please
refer to P89LPC9151/9161/9171 User manual for detail configurations.
If brownout detection is enabled the brownout condition occurs when V
brownout trip voltage and is negated when V
For correct activation of brownout detect, the V
Please see
The Power-on detect has a function similar to the brownout detect, but is designed to work
as power comes up initially, before the power supply voltage reaches a level where
brownout detect can work. The POF flag in the RSTSRC register is set to indicate an
initial power-up condition. The POF flag will remain set until cleared by software.
The P89LPC9151/9161/9171 supports three different power reduction modes. These
modes are Idle mode, Power-down mode, and total Power-down mode.
Idle mode leaves peripherals running in order to allow them to activate the processor
when an interrupt is generated. Any enabled interrupt source or reset may terminate Idle
mode.
Table 16 “Static characteristics”
Rev. 02 — 9 February 2010
Table 16 “Static characteristics”
P89LPC9151/9161/9171
for specifications.
DD
DD
rises above the brownout trip voltage.
rise and fall times must be observed.
8-bit microcontroller with 8-bit ADC
for detailed specifications.
DD
© NXP B.V. 2010. All rights reserved.
falls below the
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