MPC55xx Warning for Undefined Behavior

[Peter Dufault]

On Oct 13, 2014, at 16:00 , Joel Sherrill <Joel.Sherrill at oarcorp.com> wrote:

> 
> On 10/13/2014 2:56 PM, Peter Dufault wrote:
>> On Oct 13, 2014, at 15:22 , Peter Dufault <dufault at hda.com> wrote:
>> 
>>> This looks like an issue in the header.  I downloaded the MPC5674F Reference Manual and it does specify 479 interrupt request sources.  See table 9-2, INTC Memory Map
>>> 
>>> Base + (0x0040–0x0219)  INTC_PSRn—INTC priority select registers 2 0–479 
>> Last posting on this, because it's confused and I'll defer to someone with the hardware who can puzzle this out.
>> 
>> The Freescale manual is inconsistent - there isn't space for 479 (1-byte) registers in the specified memory range 0x0040 through 0x0219 that I am quoting above.  That amount allows for the 474 registers in the Freescale header file and not the 479 in the RTEMS header file. So if I had to guess I'd guess the RTEMS header is wrong because someone read the Freescale manual and saw it clearly say there are 479 registers.
> That sounds enormously like a typo in the manual since the warning says
> 474u.
> The compiler is catching that there isn't enough space in that array.
> 
> I am prone to change 479 to 474 as you suggested but I would like another
> opinion first.
> 
> Thanks for tracking this one down.

It's more confusing than that.  There are hardware decimation filters E through H that show up in the Freescale manual with the assignment of numbers 476 through 479, so it could be the memory range in the document that's in error and not the count of interrupt sources.

We'll leave it to the folk with the hardware.

>> Peter
>> -----------------
>> Peter Dufault
>> HD Associates, Inc.      Software and System Engineering
>> 
> 
> -- 
> Joel Sherrill, Ph.D.             Director of Research & Development
> joel.sherrill at OARcorp.com        On-Line Applications Research
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> 

Peter
-----------------
Peter Dufault
HD Associates, Inc.      Software and System Engineering