mayhem-firmware/firmware/chibios/os/hal/platforms/AVR/platform.dox

/*
    ChibiOS/RT - Copyright (C) 2006-2013 Giovanni Di Sirio

    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at

        http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

/**
 * @defgroup AVR_DRIVERS AVR Drivers
 * @details This section describes all the supported drivers on the AVR
 *          platform and the implementation details of the single drivers.
 *
 * @ingroup platforms
 */

/**
 * @defgroup AVR_HAL AVR Initialization Support
 * @details On the AVR platform the HAL driver is a stub and does not perform
 *          any platform-specific initialization, it still performs the
 *          initialization of the other drivers.
 *
 * @ingroup AVR_DRIVERS
 */

/**
 * @defgroup AVR_PAL AVR PAL Support
 * @details The AVR PAL driver uses the PORT peripherals.
 *
 * @section avr_pal_1 Supported HW resources
 * - PORTA.
 * - PORTB.
 * - PORTC.
 * - PORTD.
 * - PORTE.
 * - PORTF.
 * - PORTG.
 * .
 * @section avr_pal_2 AVR PAL driver implementation features
 * The AVR PAL driver implementation fully supports the following hardware
 * capabilities:
 * - 8 bits wide ports.
 * - Atomic set/reset functions.
 * - Output latched regardless of the pad setting.
 * - Direct read of input pads regardless of the pad setting.
 * .
 * @section avr_pal_3 Supported PAL setup modes
 * The AVR PAL driver supports the following I/O modes:
 * - @p PAL_MODE_RESET.
 * - @p PAL_MODE_UNCONNECTED.
 * - @p PAL_MODE_INPUT.
 * - @p PAL_MODE_INPUT_PULLUP.
 * - @p PAL_MODE_INPUT_ANALOG.
 * - @p PAL_MODE_OUTPUT_PUSHPULL.
 * .
 * Any attempt to setup an invalid mode is ignored.
 *
 * @section avr_pal_4 Suboptimal behavior
 * The AVR PORT is less than optimal in several areas, the limitations
 * should be taken in account while using the PAL driver:
 * - Pad/port toggling operations are not atomic.
 * - Pad/group mode setup is not atomic.
 * - Group set+reset function is not atomic.
 * - Writing on pads/groups/ports programmed as input with pull-up
 *   resistor changes the resistor setting because the output latch is
 *   used for resistor selection.
 * - The PORT registers layout on some devices is not regular (it does
 *   not have contiguous PIN, DDR, PORT registers in this order), such
 *   ports cannot be accessed using the PAL driver. For example, PORT F
 *   on ATmega128. Verify the user manual of your device.
 * .
 * @ingroup AVR_DRIVERS
 */

/**
 * @defgroup AVR_SERIAL AVR Serial Support
 * @details The AVR Serial driver uses the USART peripherals in a
 *          buffered, interrupt driven, implementation.
 *
 * @section avr_serial_1 Supported HW resources
 * The serial driver can support any of the following hardware resources:
 * - USART0.
 * - USART1.
 * .
 * @section avr_serial_2 AVR Serial driver implementation features
 * - Each USART can be independently enabled and programmed.
 * - Fully interrupt driven.
 * .
 * @ingroup AVR_DRIVERS
 */

/**
 * @defgroup AVR_I2C AVR I2C Support
 * @details The AVR I2C driver uses the TWI peripheral in an interrupt
 *          driven, implementation.
 *
 * @section avr_i2c Supported HW resources
 * The i2c driver can support the following hardware resource:
 * - I2C.
 * .
 * @ingroup AVR_DRIVERS
 */