LPC1111 NXP [NXP Semiconductors], LPC1111 Datasheet - Page 24

• Manufacturer Part Number: LPC1111
• Description: 32-bit ARM Cortex-M0 microcontroller; up to 32 kB flash and 8 kB SRAM
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
LPC1111_12_13_14_1
Product data sheet
Fig 6.
watchdog oscillator
system oscillator
IRC oscillator
IRC oscillator
LPC1111/12/13/14 clock generation block diagram
(system PLL clock select)
7.15.1.1 Internal RC oscillator
7.15.1 Crystal oscillators
SYSPLLCLKSEL
7.15 Clocking and power control
The LPC1111/12/13/14 include three independent oscillators. These are the system
oscillator, the Internal RC oscillator (IRC), and the Watchdog oscillator. Each oscillator can
be used for more than one purpose as required in a particular application.
Following reset, the LPC1111/12/13/14 will operate from the Internal RC oscillator until
switched by software. This allows systems to operate without any external crystal and the
bootloader code to operate at a known frequency.
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.
Figure 6
SYSTEM PLL
(main clock select)
MAINCLKSEL
for an overview of the LPC1111/12/13/14 clock generation.
All information provided in this document is subject to legal disclaimers.
main clock
Rev. 01 — 16 April 2010
watchdog oscillator
watchdog oscillator
system oscillator
SYSTEM CLOCK
IRC oscillator
IRC oscillator
DIVIDER
(WDT clock update enable)
(CLKOUT update enable)
CLKOUTUEN
WDTUEN
system clock
32-bit ARM Cortex-M0 microcontroller
LPC1111/12/13/14
AHBCLKCTRL[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. 2010. 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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