Overview

Description

This document covers the configuration and usage of the Hardware Abstraction Layer (HAL) for the Atmel AT91RM9200 processor. It is expected to be read in conjunction with platform HAL-specific documentation, as well as the eCos HAL specification. This processor HAL package complements the ARM architectural HAL, ARM9 variant HAL and the platform HAL. It provides functionality common to AT91RM9200-based board implementations.

This support is found in the eCos package located at packages/hal/arm/arm9/at91rm9200 within the eCos source repository.

The AT91RM9200 processor HAL package is loaded automatically when eCos is configured for an AT91RM9200-based platform. It should never be necessary to load this package explicitly. Unloading the package should only happen as a side effect of switching target hardware.

Supported Hardware

Supported features of the Atmel AT91RM9200 processor within this processor HAL package include:

• AT91RM9200-specific hardware definitions

• Interrupt controller

• Timer counters

• Serial UARTs

• MultiMedia Card Interface (MCI)

• Two-Wire Interface (TWI)

• Power saving

Support for the on-chip ethernet, interrupt-driven serial, SPI, watchdog and wallclock (RTC) features of the AT91RM9200 are also present and can be found in separate packages, outside of this processor HAL.

The watchdog hardware is also used within this HAL to perform software reset.