Overview

Description

This document covers the configuration and usage of the Hardware Abstraction Layer (HAL) for the Atmel AT91 processor family which includes the AT91R4xxxx series, the M42xxxx and M55xxxx series and the AT91SAM7S, -X and -A series. 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, AT91SAM7 variant HAL (where appropriate) and the platform HAL. It provides functionality common to all AT91-based board implementations.

This support is found in the eCos package located at packages/hal/arm/at91/var within the eCos source repository.

The AT91 processor HAL package is loaded automatically when eCos is configured for an AT91-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 AT91 processor within this processor HAL package include:

• AT91-specific hardware definitions

• Interrupt controller

• Timer counters

• Serial UARTs

Support for the interrupt-driven serial, SPI, watchdog and wallclock (RTC) features of the AT91 are also present and can be found in separate packages, outside of this processor HAL.

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