readme.txt

analog device vdsp watch dog timer tutorial.

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ADSP-BF561 EZ-KIT 

Watchdog Example

Analog Devices, Inc.
DSP Division
Three Technology Way
Norwood, MA 02062

Date Created:	11/24/03

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This example initializes both watchdog timers and enables the 4 push-buttons as interrupt sources to
prevent the watchdog interrupt from occurring.  Activity on the LEDs is a result of each Watchdog
timer expiring.

This is a dual core project. Please see section III to get familiar with the project structure.
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CONTENTS

I.	 FUNCTIONAL DESCRIPTION
II.	 OPERATION DESCRIPTION
III. 	 PROJECT STRUCTURE


I.    FUNCTIONAL DESCRIPTION

	The Watchdog demo demonstrates the initialization of the watchdog timers (WDOGA and WDOGB),
	the method to configure flags as interrupts, and the ability to hold off watchdog events by
	writing to the appropriate WDOG_STAT register.
 
	Core A initializes the LEDs as outputs and the push-buttons as interrupt inputs to the cores.
	Core A configures and registers interrupt routines and sets WDOGA for a 2 second GP Interrupt.

	Core B configures and registers interrupt routines and sets WDOGB for a 2 second GP Interrupt.

	This example utilizes the 16 LEDs 5-20 to show each WDOG's expiration.  When Core A's WDOG
	expires, LEDs 13-20 toggle.  When Core B's WDOG expires, LEDs 5-12 toggle.
	

II.  OPERATION DESCRIPTION

	- Open the project group "BF561_Watchdog.dpg" in the VisualDSP Integrated
	  Development Environment (IDDE). Follow instructions in section III.
	  
	- Under the "Project" tab, select "Build Project" (program is then loaded automatically into DSP).

	- Dipswitch SW4: set #1, 2, 3, 4 to "on", all others to "off"
	
	- Run the executables by pressing "multiprocessor run" (CTRL-F5) on the toolbar. DO NOT use the
	  single core (F5) button.  You should see LED activity on LEDs5-20 corresponding to the two
	  2-second WDOG interrupts.
	  
	- Push Button SW8 or SW9 to see the LEDs 13-20 become stagnant for ~2 seconds (resets WDOGA)
	- Push Button SW6 or SW7 to see the LEDs 5-12 become stagnant for ~2 seconds (resets WDOGB)
		- Buttons are configured as edge sensitive interrupts, therefore, holding the button down
		  does NOT continually hold off the WDOG interrupt.  Repeated pushing and releasing of
		  the button WILL continually hold off the WDOG interrupt.
	  
	- The main header file "BF561_Watchdog.h" contains #define statements for all of the project
	  constants.  It also initializes all function prototypes and interrupt handlers and includes
	  shared library header files.

		
III. PROJECT STRUCTURE

	This is a dual core project. It consists of a main project - containing only system defines and
        linker settings-
			".\BF561_Watchdog.dpj",
	four sub-projects 		- containing the source code -
			".\core A\Core_A.dpj"					( code exclusive to core A, in L1 memory)
			".\core B\core_B.dpj"					( code exclusive to core B, in L1 memory)
			".\Shared Memory L2\SM_L2.dpj"	   ( code that is shared between the cores, in on-chip L2 memory)
			".\Shared Memory L3\SM_L3.dpj" ( code that is shared between the cores, in off-chip L3 memory, SDRAM),
	and the project group file that ties everything together:
			".\BF561_Watchdog.dpg".
			
	Follow this procedure to open and compile the project:
	- open the project group (File-> Open-> Project Group)
	- Right click on the main project and re-build the project.