LPC1112FD20 NXP Semiconductors, LPC1112FD20 Datasheet - Page 47

• Manufacturer Part Number: LPC1112FD20
• Description: The LPC1112FD20 is an ARM Cortex-M0 based, low-cost 32-bit MCU, designed for 8/16-bit microcontroller applications, offering performance, low power, simple instruction set and memory addressing together with reduced code size compared to existing 8/1
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC111X
Product data sheet
Fig 14. LPC1110/11/12/13/14/15 clock generation block diagram
watchdog oscillator
system oscillator
IRC oscillator
IRC oscillator
(system PLL clock select)
7.16.1.1 Internal RC oscillator
7.16.1.2 System oscillator
SYSPLLCLKSEL
See
The IRC may be used as the clock source for the WDT, and/or as the clock that drives the
PLL and subsequently the CPU. The nominal IRC frequency is 12 MHz. The IRC is
trimmed to 1 % accuracy over the entire voltage and temperature range.
Upon power-up or any chip reset, the LPC1110/11/12/13/14/15 use the IRC as the clock
source. Software may later switch to one of the other available clock sources.
The system oscillator can be used as the clock source for the CPU, with or without using
the PLL.
The system oscillator operates at frequencies of 1 MHz to 25 MHz. This frequency can be
boosted to a higher frequency, up to the maximum CPU operating frequency, by the
system PLL.
Figure 14
SYSTEM PLL
(main clock select)
MAINCLKSEL
for an overview of the LPC1110/11/12/13/14/15 clock generation.
All information provided in this document is subject to legal disclaimers.
main clock
Rev. 7 — 1 March 2012
watchdog oscillator
watchdog oscillator
system oscillator
SYSTEM CLOCK
IRC oscillator
IRC oscillator
DIVIDER
(WDT clock update enable)
(CLKOUT update enable)
LPC1110/11/12/13/14/15
CLKOUTUEN
WDTUEN
system clock
32-bit ARM Cortex-M0 microcontroller
SYSAHBCLKCTRL[1:18]
(AHB clock enable)
CLKOUT PIN CLOCK
UART PERIPHERAL
SPI0 PERIPHERAL
SPI1 PERIPHERAL
CLOCK DIVIDER
CLOCK DIVIDER
CLOCK DIVIDER
18
WDT CLOCK
DIVIDER
DIVIDER
© NXP B.V. 2012. All rights reserved.
AHB clocks 1 to 18
(memories
and peripherals)
AHB clock 0
(system)
SPI0
UART
SPI1
WDT
CLKOUT pin
002aae514
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