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alagee
Joined: 26 Aug 2023 Posts: 2
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Internal RC with IO on PIC16F877A |
Posted: Sat Aug 26, 2023 7:16 am |
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Hi
can anyone help me find a way to choose the #FUSE for using internal RC on PIC16F877A with OCS pins as IO?
#fuses INTRC_IO
and
#fuses INTRC
do not work! |
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temtronic
Joined: 01 Jul 2010 Posts: 9168 Location: Greensville,Ontario
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Posted: Sat Aug 26, 2023 9:13 am |
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Going from memory( 2 DECADES ago...), that PIC does NOT have an internal Oscillator.
probably explains why those 'fuses' don't work for you.
You either use a xtal/2 caps OR an R/C configuration, with clk out being F/4
Again from memory.....
The datasheet. 'special functions of the CPU. chapter ???
Jay |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19358
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Posted: Sat Aug 26, 2023 9:29 am |
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Exactly right Jay.
The four oscillators are:
RC
HS
XT
LP
The RC one is using an external resistor/capacitor, not an internal oscillator.
The watchdog has it's own internal oscillator, but the CPU doesn't.
There are pin compatible later chips that do have an internal oscillator, but
the earlier chips generally did not offer this. |
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alagee
Joined: 26 Aug 2023 Posts: 2
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Posted: Sat Aug 26, 2023 11:23 pm |
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I am really grateful to have your support.
there was a misunderstanding in project definition.
The micro must have been PIC16F887 that I included PIC16F877 wrongfully.
the problem is solved.
Thank you all |
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Ttelmah
Joined: 11 Mar 2010 Posts: 19358
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Posted: Sun Aug 27, 2023 1:35 am |
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I think 'oops' officially applies!....
At least you now know 'why' the compiler was refusing to let you select
the internal oscillator. |
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