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' =========================================================================
'
' File...... COUNT.SXB
' Purpose... Demonstrates SX/B COUNT instruction
' Author.... (c) Parallax, Inc. -- All Rights Reserved
' E-mail.... support@parallax.com
' Started...
' Updated... 05 JUL 2006
'
' =========================================================================
' -------------------------------------------------------------------------
' Program Description
' -------------------------------------------------------------------------
'
' This program will count the transitions on the FreqIn (RA.0) pin for
' one second. Run the program in Debug mode, then select Poll from the
' Debug control panel.
' -------------------------------------------------------------------------
' Device Settings
' -------------------------------------------------------------------------
DEVICE SX28, OSC4MHZ, TURBO, STACKX, OPTIONX
FREQ 4_000_000
ID "COUNT"
' -------------------------------------------------------------------------
' IO Pins
' -------------------------------------------------------------------------
FreqIn VAR RA.0 ' frequency input
' -------------------------------------------------------------------------
' Constants
' -------------------------------------------------------------------------
Duration CON 1000 ' measure for one second
' -------------------------------------------------------------------------
' Variables
' -------------------------------------------------------------------------
hertz VAR Word ' measured cycles
WATCH hertz ' for Debug display
' =========================================================================
PROGRAM Start
' =========================================================================
' -------------------------------------------------------------------------
' Program Code
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Start:
DO
COUNT FreqIn, Duration, hertz ' measure frequency
BREAK ' display in Watch window
LOOP