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vsmguy
Joined: 13 Jan 2007 Posts: 91
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Timer 0 and 1 queries |
Posted: Sun Jul 11, 2010 7:01 pm |
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Reading 33023a.pdf set my ideas straight but now I have some questions:
1. Why would anyone want to enable T1SYNC?
An example scenario would be great
2. I am also intrigued by an old practice of "self-clocking" TMR0 by toggling T0SE to extract the timer0 prescaler value - but I do not get how toggling that bit increments the counter - any insights in this? |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Sun Jul 11, 2010 11:17 pm |
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Quote: |
Reading 33023a.pdf
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That's the mid-range (16F) PIC Reference manual.
http://ww1.microchip.com/downloads/en/devicedoc/33023a.pdf
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1. Why would anyone want to enable T1SYNC?
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It says right in there, in various places, why synchronous mode is required:
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14.3 Capture Mode
Note: Timer1 must be running in timer mode or synchronized counter
mode for the CCP module to use the capture feature. In asynchronous
counter mode, the capture operation may not work.
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Quote: |
14.4 Compare Mode
Note:
Timer1 must be running in Timer mode or Synchronized Counter mode if
the CCP module is using the compare feature. In Asynchronous Counter
mode, the compare operation may not work.
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12.8 Resetting Timer1 Using a CCP Trigger Output
Timer1 must be configured for either timer or synchronized counter
mode to take advantage of the special event trigger feature. If Timer1 is
running in asynchronous counter mode, this reset operation may not
work, and should not be used.
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There might be other places where it says this. |
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vsmguy
Joined: 13 Jan 2007 Posts: 91
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Re: Timer 0 and 1 queries |
Posted: Mon Jul 12, 2010 2:16 am |
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vsmguy wrote: |
2. I am also intrigued by an old practice of "self-clocking" TMR0 by toggling T0SE to extract the timer0 prescaler value - but I do not get how toggling that bit increments the counter - any insights in this? |
1. How/why does toggling the T0SE increment the prescaler?
2. If the T0CKI pin gets physically damaged, will toggling the T0SE increment the prescaler anyways? |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Mon Jul 12, 2010 12:12 pm |
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These questions should be asked on the Microchip forum. |
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vsmguy
Joined: 13 Jan 2007 Posts: 91
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Posted: Mon Jul 12, 2010 12:15 pm |
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I thought so too - and I will - but I asked here (you) anyways as you tend to do a lot of hands on experiments! |
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