HAL Port — Implementation Details
This documentation explains how the eCos HAL specification has been mapped onto the DNP/5280 hardware, and should be read in conjunction with that specification. The DNP/5280 platform HAL package complements the M68K architectural HAL, the MCFxxxx variant HAL, and the MCF5282 processor HAL. It provides functionality which is specific to the target board.
Following a hard or soft reset the HAL will initialize those devices
for which there are active device drivers. There is an exception for
RAM startup applications which depend on a ROM monitor for certain
services: the UARTs and the ethernet device will not be reinitialized
because they may be in use by RedBoot for communication with the host.
Full details of this initialization can be found in the function
For a ROM startup the HAL will perform additional initialization,
setting up the external DRAM and chip selects. Full details can be
found in the exported header
The platform HAL provides configuration options for the eCos system clock. This always uses the hardware timer PIT3, which should not be used directly by application code. The actual HAL macros for managing the clock are provided by the MCF5282 processor HAL. The specific numbers used are a characteristic of the platform because they depend on the processor speed. The gprof-based profiling code uses PIT2. Timers PIT0 and PIT1 are not used by eCos so application code is free to manipulate these as required.
The DNP/5280 platform HAL does not affect the implementation of other parts of the eCos HAL specification. The MCF5282 processor HAL, the MCFxxxx variant HAL, and the M68K architectural HAL documentation should be consulted for further details.
The platform HAL package provides a flash driver for the off-chip
AMD AM29LV640 flash chip. This driver is inactive by default, and
only becomes active if the configuration includes the generic flash
The platform HAL provides some additional functions for manipulating the LEDs and dipswitch on the DNP/EVA2_SV6 carrier board:
void hal_dnp5280_led_set(which, what)
This can be used to switch one of the LEDs on or off. The
whichargument specifies the LED and should be a number between 0 and 7. The
whatargument should be non-zero to switch the LED on, zero to switch it off. This function must not be called if the processor's QA and QB pins are not actually connected to the LEDs.
This allows application code to query the state of one of the dip
whichargument should be a number between 1 and 8.
- This allows application code to query the state of all the dip switches in one go. The result is an 8-bit number with bit 0 corresponding to dipswitch 1.
|2018-06-19||eCosPro Non-Commercial Public License|