LPC1857FET256,551 NXP Semiconductors, LPC1857FET256,551 Datasheet - Page 699

• Manufacturer Part Number: LPC1857FET256,551
• Description: IC MCU 32BIT 1MB FLASH 256LBGA
• Manufacturer: NXP Semiconductors
• Series: LPC18xxr

Specifications of LPC1857FET256,551

• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 150MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, SD/MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, LCD, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 80
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 136K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 16x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-LBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

31.1 How to read this chapter
31.2 Basic configuration
31.3 Features
31.4 General description
<Document ID>
User manual
On parts LPC1850/30/20/10 Rev ‘A’, the function of the alarm pin RTC_ALARM must be
configured in the CREG0 register
The RTC is configured as follows:
Remark: After initializing the 32 kHZ oscillator, wait for 2 sec before writing to the RTC
registers.
Table 630. RTC clocking and power 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. On the LPC18xx, the RTC is
clocked by a separate 32 kHz oscillator that produces a 1 Hz internal time reference. The
RTC is powered by its own power supply pin, VBAT, .
Clock to alarm timer register interface
32 kHz crystal oscillator output for the
counter/timer clock
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UM10430
Chapter 31: LPC18xx Real-Time Clock (RTC)
Rev. 00.13 — 20 July 2011
See
oscillator must be enabled in the CREG0 register in the CREG block (see
The RTC interrupt is connected to slot # 5 in the Event router.
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
and selected fractional second values.
Alarm interrupt can be generated for a specific date/time.
Table 630
All information provided in this document is subject to legal disclaimers.
for clocking and power control. The 1 kHz output of the 32 kHz
Rev. 00.13 — 20 July 2011
(Table
Base clock
BASE_M3_CLK
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31).
CLK_M3_BUS 150 MHz
Branch clock
-
Maximum
frequency
1024 Hz (fixed
frequency)
© NXP B.V. 2011. All rights reserved.
User manual
Table
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31).