P89LPC9151 NXP [NXP Semiconductors], P89LPC9151 Datasheet - Page 39

• Manufacturer Part Number: P89LPC9151
• Description: 8-bit microcontroller with accelerated two-clock 80C51 core, 2 kB 3 V byte-erasable flash with 8-bit ADC
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
P89LPC9151_61_71_2
Product data sheet
Fig 10. Block diagram of oscillator control
(7.3728 MHz/14.7456 MHz ± 1 %)
7.6 Watchdog oscillator option
7.7 External clock input option
7.8 Clock sources switch on the fly
(400 kHz ± 5 %)
OSCILLATOR
OSCILLATOR
CLKIN
WATCHDOG
running at 8 MHz or slower. When clock doubler option is enabled, BOE1 bit (UCFG1.5)
and BOE0 bit (UCFG1.3) are required to hold the device in reset at power-up until V
has reached its specified level.
The watchdog has a separate oscillator which has a frequency of 400 kHz, calibrated to
±5 % at room temperature. This oscillator can be used to save power when a high clock
frequency is not needed.
In this configuration, the processor clock is derived from an external source driving the
P0.5/CLKIN pin. The rate may be from 0 Hz up to 18 MHz. When the frequency above
12 MHz, BOE1 bit (UCFG1.5) and BOE0 bit (UCFG1.3) are required to hold the device in
reset at power-up until V
Remark: When using P0.5 as a clock input option, please make sure that P0.5 is
configured as input only mode.
P89LPC9151/9161/9171 can implement clock source switch in any sources of watchdog
oscillator, 7 MHz/14 MHz IRC oscillator, or external clock input during code is running.
CLKOK bit in CLKCON register is used to indicate the clock switch status. CLKOK is
cleared when starting clock source switch and set when completed. Notice that when
CLKOK is ‘0’, writing to CLKCON register is not allowed.
RC
RCCLK
Rev. 02 — 9 February 2010
RCCLK
DD
has reached its specified level.
XCLK
DIVM
TIMER 0 AND
TIMER 1
OSCCLK
P89LPC9151/9161/9171
PCLK
I
2
C-BUS
÷2
RTCS1:0
CCLK
PCLK
8-bit microcontroller with 8-bit ADC
UART
ADC1/DAC1
WDT
CPU
RTC
CLKOUT
(P89LPC9161)
002aae574
SPI
© NXP B.V. 2010. All rights reserved.
39 of 91
DD