LPC11U23FBD48 NXP Semiconductors, LPC11U23FBD48 Datasheet - Page 23

• Manufacturer Part Number: LPC11U23FBD48
• Description: The LPC11U23FBD48 is a 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/
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC11U2X
Product data sheet
Fig 7.
watchdog oscillator
system oscillator
system oscillator
IRC oscillator
IRC oscillator
LPC11U2x clocking generation block diagram
(system PLL clock select)
7.17.1.1 Internal RC oscillator
(USB clock select)
USBPLLCLKSEL
SYSPLLCLKSEL
The IRC can be used as the clock source for the WDT, and/or as the clock that drives the
system PLL and then the CPU. The nominal IRC frequency is 12 MHz.
Upon power-up, any chip reset, or wake-up from Deep power-down mode, the LPC11U2x
use the IRC as the clock source. Software can later switch to one of the other available
clock sources.
SYSTEM PLL
(main clock select)
USB PLL
MAINCLKSEL
All information provided in this document is subject to legal disclaimers.
main clock
Rev. 2 — 13 January 2012
watchdog oscillator
system oscillator
SYSTEM CLOCK
IRC oscillator
DIVIDER
(USB clock update enable)
(CLKOUT update enable)
CLKOUTUEN
USBUEN
system clock
watchdog oscillator
32-bit ARM Cortex-M0 microcontroller
IRC oscillator
USART PERIPHERAL
SYSAHBCLKCTRLn
CLKOUT PIN CLOCK
(WDT clock select)
(AHB clock enable)
USB 48 MHz CLOCK
SSP0 PERIPHERAL
SSP1 PERIPHERAL
CLOCK DIVIDER
CLOCK DIVIDER
CLOCK DIVIDER
WDCLKSEL
n
DIVIDER
DIVIDER
LPC11U2x
© NXP B.V. 2012. All rights reserved.
CPU, system control,
PMU
memories,
peripheral clocks
SSP0
UART
SSP1
USB
CLKOUT pin
WDT
002aaf892
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