LPC2144 NXP [NXP Semiconductors], LPC2144 Datasheet - Page 19

• Manufacturer Part Number: LPC2144
• Description: Single-chip 16-bit/32-bit microcontrollers; up to 512 kB flash with ISP/IAP, USB 2.0 full-speed device, 10-bit ADC and DAC
• Manufacturer: NXP [NXP Semiconductors]

NXP Semiconductors
LPC2141_42_44_46_48_3
Product data sheet
6.15.1 Features
6.16.1 Features
6.17.1 Features
6.16 Watchdog timer
6.17 Real-time clock
The purpose of the watchdog is to reset the microcontroller within a reasonable amount of
time if it enters an erroneous state. When enabled, the watchdog will generate a system
reset if the user program fails to ‘feed’ (or reload) the watchdog within a predetermined
amount of time.
The RTC is designed to provide a set of counters to measure time when normal or idle
operating mode is selected. The RTC has been designed to use little power, making it
suitable for battery powered systems where the CPU is not running continuously (Idle
mode).
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A 32-bit timer/counter with a programmable 32-bit prescaler
External event counter or timer operation
Four 32-bit capture channels per timer/counter that can take a snapshot of the timer
value when an input signal transitions, a capture event may also optionally generate
an interrupt
Four 32-bit match registers that allow:
– Continuous operation with optional interrupt generation on match
– Stop timer on match with optional interrupt generation
– Reset timer on match with optional interrupt generation
Four external outputs per timer/counter corresponding to match registers, with the
following capabilities:
– Set LOW on match
– Set HIGH on match
– Toggle on match
– Do nothing on match
Internally resets chip if not periodically reloaded
Debug mode
Enabled by software but requires a hardware reset or a watchdog reset/interrupt to be
disabled
Incorrect/Incomplete feed sequence causes reset/interrupt if enabled
Flag to indicate watchdog reset
Programmable 32-bit timer with internal pre-scaler
Selectable time period from (T
T
Measures the passage of time to maintain a calendar and clock
cy(PCLK)
4
Rev. 03 — 19 October 2007
cy(PCLK)
256
LPC2141/42/44/46/48
Single-chip 16-bit/32-bit microcontrollers
4) to (T
cy(PCLK)
2
32
© NXP B.V. 2007. All rights reserved.
4) in multiples of
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