LM3S5C51 Datasheet, PDF (57/1266 Pages) Texas Instruments – Stellaris® LM3S5C51 Microcontroller

Stellaris^® LM3S5C51 Microcontroller
1.3.4.4
1.3.4.5
1.3.4.6
CCP Pins (see page 486)
Capture Compare PWM pins (CCP) can be used by the General-Purpose Timer Module to time/count
external events using the CCP pin as an input. Alternatively, the GPTM can generate a simple PWM
output on the CCP pin.
The LM3S5C51 microcontroller includes eight Capture Compare PWM pins (CCP) that can be
programmed to operate in the following modes:
■ Capture: The GP Timer is incremented/decremented by programmed events on the CCP input.
The GP Timer captures and stores the current timer value when a programmed event occurs.
■ Compare: The GP Timer is incremented/decremented by programmed events on the CCP input.
The GP Timer compares the current value with a stored value and generates an interrupt when
a match occurs.
■ PWM: The GP Timer is incremented/decremented by the system clock. A PWM signal is generated
based on a match between the counter value and a value stored in a match register and is output
on the CCP pin.
Hibernation Module (see page 289)
The Hibernation module provides logic to switch power off to the main processor and peripherals
and to wake on external or time-based events. The Hibernation module includes power-sequencing
logic and has the following features:
■ 32-bit real-time counter (RTC)
– Two 32-bit RTC match registers for timed wake-up and interrupt generation
– RTC predivider trim for making fine adjustments to the clock rate
■ Two mechanisms for power control
– System power control using discrete external regulator
– On-chip power control using internal switches under register control
■ Dedicated pin for waking using an external signal
■ RTC operational and hibernation memory valid as long as V_BAT is valid
■ Low-battery detection, signaling, and interrupt generation
■ Clock source from a 32.768-kHz external oscillator or a 4.194304-MHz crystal; 32.768-kHz
external oscillator can be used for main controller clock
■ 64 32-bit words of battery-backed memory to save state during hibernation
■ Programmable interrupts for RTC match, external wake, and low battery events
Watchdog Timers (see page 525)
A watchdog timer is used to regain control when a system has failed due to a software error or to
the failure of an external device to respond in the expected way. The Stellaris Watchdog Timer can
generate an interrupt or a reset when a time-out value is reached. In addition, the Watchdog Timer
is ARM FiRM-compliant and can be configured to generate an interrupt to the microcontroller on its
January 23, 2012
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