UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
939 of 1269
36.1 How to read this chapter
The event monitor/recorder is available on parts with on-chip flash only.
36.2 Basic configuration
The event monitor/recorder is configured together with the RTC:
•
See
for clocking and power control. The 1 kHz output of the 32 kHz
oscillator must be enabled in the CREG0 register in the CREG block (see
).
•
The event monitor/recorder raises an RTC interrupt which is connected to slot # 5 in
the Event router and slot #47 in the NVIC.
•
Enable the SAMPLE pin for monitoring the sample clock in the CREG0 register (see
).
36.3 Features
•
Supports three digital event inputs in the RTC power domain.
•
An event is a level change at the digital event inputs.
•
For each event channel, two timestamps mark the first and the last occurrence of an
event. Each channel also has a dedicated counter tracking the total number of events.
Timestamp values are taken from the RTC.
•
Runs in RTC power domain, independent of system power supply.
•
Can run in Deep Power Down mode if VBAT is present.
•
Very low-power consumption.
•
Interrupt available if system is up.
•
A qualified event can be used as a wake-up trigger.
•
State of event inputs accessible by software through general purpose I/O.
36.4 Applications
The event monitor/recorder is used to record tampering events in sealed product
enclosures. Sensors report any attempt to open the enclosure, or to tamper with the
device in any other way. The primary purpose of the Event Monitor/Recorder is to store
records of such events when the device is powered only by the backup battery.
UM10503
Chapter 36: LPC43xx Event monitor/recorder
Rev. 1.3 — 6 July 2012
User manual
Table 811. RTC and event monitor/recorder clocking and power control
Base clock
Branch clock Operating frequency
Clock to the RTC and event
monitor/router register interface
BASE_M4_CLK
CLK_M4_BUS up to 204 MHz
32 kHz crystal oscillator output
for the RTC counter/timer clock
-
-
1024 Hz (fixed frequency);
the RTC receives an
internal 1 Hz clock.