readme.txt

bf535 rtc example code.

ADSP-BF535 EZ-KIT Lite rtc Demo

Analog Devices, Inc.
DSP Division
Three Technology Way
P.O. Box 9106
Norwood, MA 02062


Date Created:	1/30/02

This directory contains example ADSP-BF535 code that demonstrates the use of
the real time clock and general purpose I/O pins by blinking LEDs on the board upon a 
seconds interrupt. 

Files contained in this directory:

readme.txt		this file
rtc.asm			assembly file for the real time clock routine 
rtc.dpj			VisualDSP++ project file
ADSP-BF535_asm.ldf	linker description file 
 _________________________________________________________________

CONTENTS

I.	FUNCTION/ALGORITHM DESCRIPTION
II.	IMPLEMENTATION DESCRIPTION
III.	OPERATION DESCRIPTION


I.  FUNCTION/ALGORITHM DESCRIPTION

The rtc demo contains an implementation of a subroutine that utilizes the real time clock 
to generate an interrupt every second.  LED 1 blinks when the seconds interrupt is processed.


II.  IMPLEMENTATION DESCRIPTION

The ADSP-BF535 is loaded with the rtc program.
The main modules perform the following:

1. The GP I/O PF1 is set to output.
2. The real time clock seconds interrupt is enabled.
3. Program code remains in a waiting loop.
4. Upon seconds interrupt generation, program flow jumps to interrupt service routine.
5. In interrupt service routine, LED 1 is programmed to blink.
6. Upon completion of interrupt service routine, program flow jumps back to waiting loop.
7. Steps 4, 5, 6, and 7 repeat.


III.  OPERATION DESCRIPTION

- Open the project "rtc.dpj" in the VisualDSP Integrated Development and Debugger Environment (IDDE).
- Under the "Project" tab, select "Build Project".
- Open a ADSP-BF535 EZ-KIT Lite session in the Debugger.
- Load "rtc.DXE" 
- Place breakpoints as desired to see the operation of the program.
- Focus on the ADSP-BF535 and select "RUN" from the menu bar.
- View the LEDs on the EZ-KIT Lite to see the real time clock in action.