RE: Re: ISR Function

Set your PIT to interrupt every 100ms.  From within the PIT ISR, simply
call DAC ( ).  No need to pass the parameters x and y since they are
global variables.  If they are not global, make them global.
 
If DAC function and main will both modify x or y, you have to protect
them within main whilst modifying i.e. temporary disable PIT interrupt
whilst modifying.
 
 

	-----Original Message-----
	From: [email protected] [mailto:[email protected]] On
Behalf Of Rajesh
	Sent: Thursday, June 29, 2006 11:40 PM
	To: [email protected]
	Subject: [MPC500] Re: ISR Function
	
	

	Hi,
	
	I think I was unable to put my question. Sorry for that, here it
is:
	
	My code is like this:
	
	main()
	{
	
	function1(); // this will execute and output of this function is
x,y 
	//which are global variables.
	}
	Now my DAC(x,y) function will take this x,y as input.I am trying
to 
	execute this DAC(x,y) function at every 100 milisec, nomatter
where I 
	am in the main loop at that time.
	I am using COdeWarrior Compiler 8.1.
	
	-regards
	Rajesh
	
	--- In [email protected] <mailto:MPC500%40yahoogroups.com>
, "Dobbin Allan-r11834" 
	<Allan.Dobbin@...> wrote:
	>
	> Rajesh, perhaps I don't understand your question - do you have
PIT
	> working and interrupting, but you just don't know how to call
a C
	> function from assembler?
	> 
	> Most compilers allow you to specify a function is an interrupt

	function,
	> i.e. with Diab compiler you can do the following:
	> 
	> INTERRUPT void external_interrupt (void)
	> {
	> "
	> "
	> PitIsr (); /* handle PIT interrupt */
	> }
	> 
	> so in your vector area, you have
	> .org base_add + 0x500 ;External Interrupt Exception
	> b external_interrupt
	> 
	> So now calling your DAC function within PitIsr is just like
any 
	other C
	> code i.e. DAC(x,y);
	> 
	> The question of where do x,y come from within an ISR - perhaps

	these are
	> global variables?
	> 
	> I'm not sure if this is what you were asking.
	> 
	> - Allan 
	> 
	> 
	> 
	> 
	> -----Original Message-----
	> From: [email protected] <mailto:MPC500%40yahoogroups.com>
[mailto:[email protected] <mailto:MPC500%40yahoogroups.com> ] 
	On
	> Behalf Of Rajesh
	> Sent: Thursday, June 29, 2006 4:21 AM
	> To: [email protected] <mailto:MPC500%40yahoogroups.com> 
	> Subject: [MPC500] ISR Function
	> 
	> 
	> 
	> 
	> Hi everyone,
	> I am working with MPC566 and I have a function DAC(x,y), 
	> i.e. a D/A converter function, which I want to execute on
	> Interrupt 
	> at every 100 ms.
	> I am using a PIT and can set time between 64 msecs to 4.19 
	secs.
	> Can anyone please tell me how to call this function in an ISR?
	> 
	> -regards
	> Rajesh
	> 
	> 
	> 
	> 
	> 
	> 
	> 
	> [Non-text portions of this message have been removed]
	>
	
	

	 



[Non-text portions of this message have been removed]



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