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LM3S2B93 Datasheet, PDF (62/1194 Pages) Texas Instruments – Stellaris® LM3S2B93 Microcontroller | |||
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Architectural Overview
1.3.5.7
The LM3S2B93 microcontroller has two Watchdog Timer modules: Watchdog Timer 0 uses the
system clock for its timer clock; Watchdog Timer 1 uses the PIOSC as its timer clock. The Stellaris
Watchdog Timer module has the following features:
â 32-bit down counter with a programmable load register
â Separate watchdog clock with an enable
â Programmable interrupt generation logic with interrupt masking
â Lock register protection from runaway software
â Reset generation logic with an enable/disable
â User-enabled stalling when the microcontroller asserts the CPU Halt flag during debug
Programmable GPIOs (see page 417)
General-purpose input/output (GPIO) pins offer flexibility for a variety of connections. The Stellaris
GPIO module is comprised of nine physical GPIO blocks, each corresponding to an individual GPIO
port. The GPIO module is FiRM-compliant (compliant to the ARM Foundation IP for Real-Time
Microcontrollers specification) and supports 0-67 programmable input/output pins. The number of
GPIOs available depends on the peripherals being used (see âSignal Tablesâ on page 1047 for the
signals available to each GPIO pin).
â Up to 67 GPIOs, depending on configuration
â Highly flexible pin muxing allows use as GPIO or one of several peripheral functions
â 5-V-tolerant in input configuration
â Two means of port access: either Advanced High-Performance Bus (AHB) with better back-to-back
access performance, or the legacy Advanced Peripheral Bus (APB) for backwards-compatibility
with existing code
â Fast toggle capable of a change every clock cycle for ports on AHB, every two clock cycles for
ports on APB
â Programmable control for GPIO interrupts
â Interrupt generation masking
â Edge-triggered on rising, falling, or both
â Level-sensitive on High or Low values
â Bit masking in both read and write operations through address lines
â Can be used to initiate an ADC sample sequence
â Pins configured as digital inputs are Schmitt-triggered
â Programmable control for GPIO pad configuration
â Weak pull-up or pull-down resistors
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January 20, 2012
Texas Instruments-Production Data
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