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ICSP in PIC18F4550 using LVP enabled

at89atbits

Sep 20, 2014
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I want to program my PIC18F4550 TQFP in LVP mode using ICSP.
However I am unsure of how PGM is supposed to be connected.
I read the datasheet and I searched online but I haven't gotten a clear view of the PGM pin connection yet.
Can someone please help me with the circuit for PGM pin on PIC18F4550 so that i can program my PIC in low voltage.
 

Gryd3

Jun 25, 2014
4,098
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Jun 25, 2014
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I want to program my PIC18F4550 TQFP in LVP mode using ICSP.
However I am unsure of how PGM is supposed to be connected.
I read the datasheet and I searched online but I haven't gotten a clear view of the PGM pin connection yet.
Can someone please help me with the circuit for PGM pin on PIC18F4550 so that i can program my PIC in low voltage.
Forgive my ignorance, but my understanding is that the PIC itself requires 12V to program. (The USB programmers have circuitry to supply this.)
 

Arouse1973

Adam
Dec 18, 2013
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Page 312 of datasheet
"
While programming using Single-Supply Programming,
VDD is applied to the MCLR/VPP/RE3 pin as in
normal execution mode. To enter Programming mode,
VDD is applied to the PGM pin."

Adam
 

Arouse1973

Adam
Dec 18, 2013
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Forgive my ignorance, but my understanding is that the PIC itself requires 12V to program. (The USB programmers have circuitry to supply this.)

That's one way to do it.
 

Gryd3

Jun 25, 2014
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Just went through the datasheet for that one.
Self-Programmability: These devices can write to
their own program memory spaces under internal
software control. By using a bootloader routine,
located in the protected Boot Block at the top of
program memory, it becomes possible to create an
application that can update itself in the field.

I like this feature ;)

And I was incorrect on the 12V requirement for this particular PIC
 

Arouse1973

Adam
Dec 18, 2013
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It also means for safety critical applications if one micro stops working a supervisor micro can re-program it.
Adam
 
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