LM3S1937 Datasheet, PDF (44/673 Pages) Texas Instruments – Stellaris® LM3S1937 Microcontroller

Architectural Overview
1.4.1.5
1.4.1.6
1.4.2
1.4.2.1
1.4.3
System Control Block (SCB) (see page 94)
The SCB provides system implementation information and system control, including configuration,
control, and reporting of system exceptions.
Memory Protection Unit (MPU) (see page 94)
The MPU supports the standard ARMv7 Protected Memory System Architecture (PMSA) model.
The MPU provides full support for protection regions, overlapping protection regions, access
permissions, and exporting memory attributes to the system.
Motor Control Peripherals
To enhance motor control, the LM3S1937 controller features Pulse Width Modulation (PWM) outputs.
PWM
Pulse width modulation (PWM) is a powerful technique for digitally encoding analog signal levels.
High-resolution counters are used to generate a square wave, and the duty cycle of the square
wave is modulated to encode an analog signal. Typical applications include switching power supplies
and motor control.
On the LM3S1937, PWM motion control functionality can be achieved through:
■ Dedicated, flexible motion control hardware using the PWM pins
■ The motion control features of the general-purpose timers using the CCP pins
PWM Pins (see page 553)
The LM3S1937 PWM module consists of three PWM generator blocks and a control block. Each
PWM generator block contains one timer (16-bit down or up/down counter), two comparators, a
PWM signal generator, a dead-band generator, and an interrupt/ADC-trigger selector. The control
block determines the polarity of the PWM signals, and which signals are passed through to the pins.
Each PWM generator block produces two PWM signals that can either be independent signals or
a single pair of complementary signals with dead-band delays inserted. The output of the PWM
generation blocks are managed by the output control block before being passed to the device pins.
CCP Pins (see page 333)
The General-Purpose Timer Module's CCP (Capture Compare PWM) pins are software programmable
to support a simple PWM mode with a software-programmable output inversion of the PWM signal.
Fault Pin (see page 559)
The LM3S1937 PWM module includes one fault-condition handling input to quickly provide low-latency
shutdown and prevent damage to the motor being controlled.
Analog Peripherals
To handle analog signals, the LM3S1937 microcontroller offers an Analog-to-Digital Converter
(ADC).
For support of analog signals, the LM3S1937 microcontroller offers one analog comparator.
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June 18, 2012
Texas Instruments-Production Data