FX2LP/FX1 External Interrupts
------------------------------


The purpose of this example is to demonstrate that the
functioning of External interrupts  (INT0, INT1, INT4, INT5 and INT6) and
how toset them up.


This directory contains the frameworks fw.c,  the test program extr_intr.c
and the external interrupt service routines isr.c.  This was compiled 
using micro vision2.  

NOTE:  The  USBJmpTb.a51  is  added to  the project  directory.  Note  that this
is the  not the default   USBJmpTb.obj  file.  This  file  is a modified  version
of the default  one.  Please refer to the comments included in the  USBJmpTb.a51
file.



To run the test
(1) Download extr_intr.hex using the control panel 
(2) Use a function generator to trigger the interrupts.  
    Set the FG to generate a square wave of frequency of 1 KHZ
    NOTE:  Make sure that the square wave is of 1 KHz on the scope
(3) Connect the probes to the corresponding external interrupt pin 
(4) The corresponding pins  on PORTC will toggle on the appropriate edge of 
    the signal connected to the external interrupt pin

External Interrupt            External                 PORTA pin toggled
     pin                      Interrupt                  in the ISR

      PA0            ---->      INT0          ---->           PC0
      PA1            ---->      INT1          ---->           PC1
      INT4           ---->      INT4          ---->           PC4
      INT5           ---->      INT5          ---->           PC5
      PE5            ---->      INT6          ---->           PC6