Got it.  Apparently PEIE *is* required when I'm not using interrupt=20
priorities (compatibility mode).

Cheers,
-Neil.


On 8/19/2015 7:06 PM, Neil wrote:
> According to the datasheet, I don't need PEIE for timer 2.  I'm not
> setting it and I am still getting the port bit toggling... it's just not
> changing as I change PR4.
> Page 114 here... http://ww1.microchip.com/downloads/en/DeviceDoc/41412F.p=
df
>
> I need to go investigate the priorities in detail again.
>
> Cheers,
> -Neil.
>
>
>
> On 8/19/2015 5:55 PM, William Bross wrote:
>> And shouldn't the PEIE bit in INTCON be set also?  Not sure of that one
>> without the datasheet in front of me.
>> BB
>>
>> William Bross wrote:
>>
>>> Hi Neil,
>>> I gave it a quick scan and it looks pretty straightforward to me.  Is
>>> your port bit set to an output?  Toggling the LAT reg?
>>> Bill
>>>
>>>
>>> Neil wrote:
>>>
>>>   =20
>>>
>>>> Would appreciate a fresh pair of eye here please, as I must be missing
>>>> something very basic.
>>>>
>>>> I'm using Timer4 on a 18F24K22 to generate repeated pulses (C18 v3.46)=
,
>>>> but changing the PR4 match value does not seem to have any effect, and
>>>> changing the prescale value seems to give odd results. This is a brief
>>>> section of what I have...
>>>>
>>>>      T4CON =3D 0b00000101;
>>>>      PR4 =3D 50;
>>>>      PIE5bits.TMR4IE =3D 1;
>>>>      RCONbits.IPEN =3D 0;                // Disable interrupt prioriti=
es
>>>>      INTCONbits.GIE =3D 1;
>>>>
>>>> The interrupt service routine...
>>>>      if (PIR5bits.TMR4IF)
>>>>      {
>>>>          ... < Toggle PORT bit here for logic analyzer > ...
>>>>          ... other code here ...
>>>>          PIR5bits.TMR4IF =3D 0;
>>>>      }    // Timer-1 interrupt
>>>>
>>>> With this, I get regular pulses on the logic analyzer.
>>>> Changing PR4 has no effect on the timing.
>>>> Now, if I change T4CON to 0b00001101, nothing changes.  0b00010101
>>>> also.  0b00110101 changes the timing though, to double the previous pe=
riod.
>>>> I tried Timer-2 similarly and got the same results.
>>>> Currently I've worked around the issue by using timer-1, but would lik=
e
>>>> to know what's going on here.
>>>>
>>>> Anyone see what am I missing here?
>>>>
>>>> Cheers,
>>>> -Neil.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>     =20
>>>>
>>>   =20
>>>

--=20
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