LM3S5D56 Datasheet, PDF (54/1146 Pages) Texas Instruments – Stellaris® LM3S5D56 Microcontroller

Architectural Overview
1.3.4.2
■ Design optimizations for improved bus access performance between µDMA controller and the
processor core
– µDMA controller access is subordinate to core access
– RAM striping
– Peripheral bus segmentation
■ Data sizes of 8, 16, and 32 bits
■ Transfer size is programmable in binary steps from 1 to 1024
■ Source and destination address increment size of byte, half-word, word, or no increment
■ Maskable peripheral requests
■ Interrupt on transfer completion, with a separate interrupt per channel
System Control and Clocks (see page 183)
System control determines the overall operation of the device. It provides information about the
device, controls power-saving features, controls the clocking of the device and individual peripherals,
and handles reset detection and reporting.
■ Device identification information: version, part number, SRAM size, Flash memory size, and so
on
■ Power control
– On-chip fixed Low Drop-Out (LDO) voltage regulator
– Hibernation module handles the power-up/down 3.3 V sequencing and control for the core
digital logic and analog circuits
– Low-power options for microcontroller: Sleep and Deep-sleep modes with clock gating
– Low-power options for on-chip modules: software controls shutdown of individual peripherals
and memory
– 3.3-V supply brown-out detection and reporting via interrupt or reset
■ Multiple clock sources for microcontroller system clock
– Precision Oscillator (PIOSC): On-chip resource providing a 16 MHz ±1% frequency at room
temperature
• 16 MHz ±3% across temperature
• Can be recalibrated with 7-bit trim resolution
• Software power down control for low power modes
– 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
54
January 23, 2012
Texas Instruments-Production Data