LM3S5739 Datasheet, PDF (49/856 Pages) Texas Instruments – Stellaris® LM3S5739 Microcontroller

Stellaris® LM3S5739 Microcontroller
1.4.1.5
1.4.1.6
1.4.1.7
1.4.2
1.4.2.1
1.4.3
1.4.3.1
System Control Block (SCB) (see page 100)
The SCB provides system implementation information and system control, including configuration,
control, and reporting of system exceptions.
Memory Protection Unit (MPU) (see page 100)
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.
Direct Memory Access (see page 294)
The LM3S5739 microcontroller includes a Direct Memory Access (DMA) controller, known as
micro-DMA (μDMA). The μDMA controller provides a way to offload data transfer tasks from the
Cortex-M3 processor, allowing for more efficient use of the processor and the expanded available
bus bandwidth. The μDMA controller can perform transfers between memory and peripherals. It
has dedicated channels for each supported peripheral and can be programmed to automatically
perform transfers between peripherals and memory as the peripheral is ready to transfer more data.
The μDMA controller also supports sophisticated transfer modes such as ping-pong and
scatter-gather, which allows the processor to set up a list of transfer tasks for the controller.
Motor Control Peripherals
To enhance motor control, the LM3S5739 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 LM3S5739, PWM motion control functionality can be achieved through:
■ The motion control features of the general-purpose timers using the CCP pins
CCP Pins (see page 413)
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.
Analog Peripherals
To handle analog signals, the LM3S5739 microcontroller offers an Analog-to-Digital Converter
(ADC).
For support of analog signals, the LM3S5739 microcontroller offers two analog comparators.
ADC (see page 465)
An analog-to-digital converter (ADC) is a peripheral that converts a continuous analog voltage to a
discrete digital number.
The LM3S5739 ADC module features 10-bit conversion resolution and supports eight input channels,
plus an internal temperature sensor. Four buffered sample sequences allow rapid sampling of up
to eight analog input sources without controller intervention. Each sample sequence provides flexible
November 17, 2011
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