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Sophi
Joined: 14 Jun 2005 Posts: 64
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RS232- #fuses NOLVP |
Posted: Wed Jun 29, 2005 10:15 am |
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hi-
Please can someone tell me why NOLVP is always included in the "#fuses" line, and why the CCS compiler won't let me use it?
Also- I am using stdio.h from Spark Fun- is there a different stdio.h file I should be using?
Thanks-
Sophi
My header code:
#include <16c74a.H>
#device ICD=TRUE
#fuses HS,NOPROTECT,NOWDT,NOBROWNOUT,PUT//,NOLVP // changed to HS for 20 mHz (NOLVP needed?)
#use delay(clock=20000000) // adjust for resonator frequency
#include <LCD2_877A.c>
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7)
#include <stdio.h> |
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treitmey
Joined: 23 Jan 2004 Posts: 1094 Location: Appleton,WI USA
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Posted: Wed Jun 29, 2005 10:24 am |
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I think we are just trying to keep people out of trouble. Go ahead and use it if you know how. My 18F452 has this note
Quote: | "Note 1: While in Low Voltage ICSP mode, the
RB5 pin can no longer be used as a general
purpose I/O pin, and should be held
low during normal operation to protect
against inadvertent ICSP mode entry.
2: When using Low Voltage ICSP programming
(LVP), the pull-up on RB5 becomes
disabled. If TRISB bit 5 is cleared,
thereby setting RB5 as an output, LATB
bit 5 must also be cleared for proper
operation." |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Wed Jun 29, 2005 2:03 pm |
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Quote: |
My header code:
#include <16c74a.H>
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Quote: | Please can someone tell me why NOLVP is always included in
the "#fuses" line, and why the CCS compiler won't let me use it? |
Your PIC doesn't have Low Voltage Programming mode. So the CCS
fuse settings of LVP and NOLVP don't apply to your PIC.
You can check the allowable fuse settings by looking at the top
of the 16c74a.h file. That file is in this folder:
c:\Program Files\Picc\Devices
You can also check the data sheet of the PIC. Look in the section
on "Special Features of the CPU". If the PIC has low voltage
programming mode, then there will be a section on it. |
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