OM13008,598 NXP Semiconductors, OM13008,598 Datasheet - Page 11

• Manufacturer Part Number: OM13008,598
• Description: BOARD LPC XPRESSO LPC122X
• Manufacturer: NXP Semiconductors
• Series: LPCXpressor

Specifications of OM13008,598

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-6642; OM13008

4.1 How to read this chapter
4.2 Introduction
4.3 Pin description
4.4 General description
UM10441
User manual
The system control block is identical on all LPC122x parts.
The system configuration block controls oscillators, start logic, and clock generation of the
LPC122x. Also included in this block are registers for setting the priority for AHB access
and a register for remapping flash, SRAM, and ROM memory areas.
Table 5
Table 5.
See
Following reset, the LPC122x will operate from the Internal RC oscillator until switched by
software. This allows systems to operate without any external crystal and the boot loader
code to operate at a known frequency.
The SYSAHBCLKCTRL register gates the system clock to the various peripherals and
memories. UART0/1, SSP, the RTC, and the SysTick timer have individual clock dividers
to derive peripheral clocks from the main clock.
The watchdog clock can be derived from the oscillator output or the main clock.
The main clock, and the clock outputs from the IRC, the system oscillator, and the
watchdog oscillator can be observed directly on the CLKOUT pin.
Pin name
CLKOUT
PIO0_0 to PIO0_11
UM10441
Chapter 4: LPC122x System control (SYSCON)
Rev. 1.1 — 10 March 2011
Figure 3
shows pins that are associated with system control block functions.
Pin summary
for an overview of the LPC122x Clock Generation Unit (CGU).
All information provided in this document is subject to legal disclaimers.
Rev. 1.1 — 10 March 2011
Pin direction
O
I
Pin description
Clockout pin
Start logic wake-up pins port 0
© NXP B.V. 2011. All rights reserved.
User manual
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