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LM3S5D91 Datasheet, PDF (59/1340 Pages) Texas Instruments – Stellaris® LM3S5D91 Microcontroller | |||
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Stellaris® LM3S5D91 Microcontroller
1.3.5.3
â Main Oscillator (MOSC): A frequency-accurate clock source by one of two means: an external
single-ended clock source is connected to the OSC0 input pin, or an external crystal is
connected across the OSC0 input and OSC1 output pins.
⢠External crystal used with or without on-chip PLL: select supported frequencies from 1
MHz to 16.384 MHz.
⢠External oscillator: from DC to maximum device speed
â Internal 30-kHz Oscillator: on chip resource providing a 30 kHz ± 50% frequency, used during
power-saving modes
â Flexible reset sources
â Power-on reset (POR)
â Reset pin assertion
â Brown-out reset (BOR) detector alerts to system power drops
â Software reset
â Watchdog timer reset
â MOSC failure
Programmable Timers (see page 532)
Programmable timers can be used to count or time external events that drive the Timer input pins.
Each GPTM block provides two 16-bit timers/counters that can be configured to operate independently
as timers or event counters, or configured to operate as one 32-bit timer or one 32-bit Real-Time
Clock (RTC). Timers can also be used to trigger analog-to-digital (ADC) conversions.
The General-Purpose Timer Module (GPTM) contains four GPTM blocks with the following functional
options:
â Operating modes:
â 16- or 32-bit programmable one-shot timer
â 16- or 32-bit programmable periodic timer
â 16-bit general-purpose timer with an 8-bit prescaler
â 32-bit Real-Time Clock (RTC) when using an external 32.768-KHz clock as the input
â 16-bit input-edge count- or time-capture modes
â 16-bit PWM mode with software-programmable output inversion of the PWM signal
â Count up or down
â Daisy chaining of timer modules to allow a single timer to initiate multiple timing events
â ADC event trigger
â User-enabled stalling when the microcontroller asserts CPU Halt flag during debug (excluding
RTC mode)
January 22, 2012
59
Texas Instruments-Production Data
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