LPC1820FET100 NXP Semiconductors, LPC1820FET100 Datasheet - Page 86

• Manufacturer Part Number: LPC1820FET100
• Description: The LPC1820FET100 is a high-performance, cost-effective Cortex-M3 microcontroller featuring 168 kB of SRAM, and advanced peripherals including High Speed USB 2
• Manufacturer: NXP Semiconductors

NXP Semiconductors
LPC1850_30_20_10
Preliminary data sheet
7.16.2.1 Features
7.17.1.1 Features
7.16.2 Digital-to-Analog Converter (DAC)
7.17.1 RTC
7.17.2 Alarm timer
7.18.1 Configuration registers (CREG)
7.17 Peripherals in the RTC power domain
7.18 System control
The Real Time Clock (RTC) is a set of counters for measuring time when system power is
on, and optionally when it is off. It uses very little power when its registers are not being
accessed by the CPU, especially reduced power modes. The RTC is clocked by a
separate 32 kHz oscillator that produces a 1 Hz internal time reference and is powered by
its own power supply pin, VBAT.
The alarm timer is a 16-bit timer and counts down at 1 kHz from a preset value generating
alarms in intervals of up to 1 min. The counter triggers a status bit when it reaches 0x00
and asserts an interrupt if enabled.
The alarm timer is part of the RTC power domain and can be battery powered.
The following settings are controlled in the configuration register block:
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10-bit resolution
Monotonic by design (resistor string architecture)
Controllable conversion speed
Low power consumption
Measures the passage of time to maintain a calendar and clock. Provides seconds,
minutes, hours, day of month, month, year, day of week, and day of year.
Ultra-low power design to support battery powered systems. Uses power from the
CPU power supply when it is present.
Dedicated battery power supply pin.
RTC power supply is isolated from the rest of the chip.
Calibration counter allows adjustment to better than 1 sec/day with 1 sec resolution.
Periodic interrupts can be generated from increments of any field of the time registers.
Alarm interrupt can be generated for a specific date/time.
BOD trip settings
Oscillator output
DMA-to-peripheral muxing
Ethernet mode
Memory mapping
All information provided in this document is subject to legal disclaimers.
Rev. 3.1 — 15 December 2011
32-bit ARM Cortex-M3 microcontroller
LPC1850/30/20/10
© NXP B.V. 2011. All rights reserved.
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