LM3S5D56 Datasheet, PDF (53/1146 Pages) Texas Instruments – Stellaris® LM3S5D56 Microcontroller

Stellaris^® LM3S5D56 Microcontroller
1.3.4.1
■ Eight Capture Compare PWM (CCP) pins
■ Lower-power battery-backed Hibernation module
■ Real-Time Clock in Hibernation module
■ Two Watchdog Timers
– One timer runs off the main oscillator
– One timer runs off the precision internal oscillator
■ Up to 33 GPIOs, depending on configuration
– Highly flexible pin muxing allows use as GPIO or one of several peripheral functions
– Independently configurable to 2, 4 or 8 mA drive capability
– Up to 4 GPIOs can have 18 mA drive capability
The following sections provide more detail on each of these functions.
Direct Memory Access (see page 356)
The LM3S5D56 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 available bus
bandwidth. The μDMA controller can perform transfers between memory and peripherals. It has
dedicated channels for each supported on-chip module and can be programmed to automatically
perform transfers between peripherals and memory as the peripheral is ready to transfer more data.
The μDMA controller provides the following features:
■ ARM PrimeCell^® 32-channel configurable µDMA controller
■ Support for memory-to-memory, memory-to-peripheral, and peripheral-to-memory in multiple
transfer modes
– Basic for simple transfer scenarios
– Ping-pong for continuous data flow
– Scatter-gather for a programmable list of arbitrary transfers initiated from a single request
■ Highly flexible and configurable channel operation
– Independently configured and operated channels
– Dedicated channels for supported on-chip modules
– Primary and secondary channel assignments
– One channel each for receive and transmit path for bidirectional modules
– Dedicated channel for software-initiated transfers
– Per-channel configurable priority scheme
– Optional software-initiated requests for any channel
■ Two levels of priority
January 23, 2012
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