LM3S101 Datasheet, PDF (78/445 Pages) List of Unclassifed Manufacturers – Microcontroller

Cortex-M3 Peripherals
3
3.1
3.1.1
Cortex-M3 Peripherals
This chapter provides information on the Stellaris^® implementation of the Cortex-M3 processor
peripherals, including:
■ SysTick (see page 78)
Provides a simple, 24-bit clear-on-write, decrementing, wrap-on-zero counter with a flexible
control mechanism.
■ Nested Vectored Interrupt Controller (NVIC) (see page 79)
– Facilitates low-latency exception and interrupt handling
– Controls power management
– Implements system control registers
■ System Control Block (SCB) (see page 81)
Provides system implementation information and system control, including configuration, control,
and reporting of system exceptions.
Table 3-1 on page 78 shows the address map of the Private Peripheral Bus (PPB). Some peripheral
register regions are split into two address regions, as indicated by two addresses listed.
Table 3-1. Core Peripheral Register Regions
Address
Core Peripheral
Description (see page ...)
0xE000.E010-0xE000.E01F
System Timer
78
0xE000.E100-0xE000.E4EF
0xE000.EF00-0xE000.EF03
Nested Vectored Interrupt Controller
79
0xE000.ED00-0xE000.ED3F
System Control Block
81
0xE000.ED90-0xE000.ED93
MPU Type Register
Reads as zero, indicated the
MPU is not implemented^a
a. Software can read the MPU Type Register at 0xE000.ED90 to test for the presence of a memory protection unit (MPU).
Functional Description
This chapter provides information on the Stellaris implementation of the Cortex-M3 processor
peripherals: SysTick, NVIC, SCB and MPU.
System Timer (SysTick)
Cortex-M3 includes an integrated system timer, SysTick, which provides a simple, 24-bit
clear-on-write, decrementing, wrap-on-zero counter with a flexible control mechanism. The counter
can be used in several different ways, for example as:
■ An RTOS tick timer that fires at a programmable rate (for example, 100 Hz) and invokes a SysTick
routine.
■ A high-speed alarm timer using the system clock.
■ A variable rate alarm or signal timer—the duration is range-dependent on the reference clock
used and the dynamic range of the counter.
■ A simple counter used to measure time to completion and time used.
78
July 14, 2014
Texas Instruments-Production Data