According to the datasheet, I don't need PEIE for timer 2.  I'm not=20
setting it and I am still getting the port bit toggling... it's just not=20
changing as I change PR4.
Page 114 here... http://ww1.microchip.com/downloads/en/DeviceDoc/41412F.pdf

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 priorities
>>>     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 per=
iod.
>>> I tried Timer-2 similarly and got the same results.
>>> Currently I've worked around the issue by using timer-1, but would like
>>> to know what's going on here.
>>>
>>> Anyone see what am I missing here?
>>>
>>> Cheers,
>>> -Neil.
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>    =20
>>>
>>  =20
>>

--=20
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