I am starting this thread in the hope that we can make it a sticky. The goal is to post known solutions for bugs related to MPLAB and all PIC compilers.
The only sure way I know of fixing the C018i error is to specify the lib path from PROJECT>BUILD_OPTIONS_PROJECT
Select the DIRECTORIES tab and followed by "LIBRARY SEARCH PATH" from the drop down box "show directories for". Add the path C:\MCC18\lib
The following was posted by Pommie in another thread.
I have today converted a project from BoostC to C18 and had a rather nasty bug. I finally tracked it down to one bit of code that wasn't working correctly. Here is that code in isolation,
What this code should do is find the first non zero bit in temp and so count should contain 11 after it executes. Well, it doesn't, it contains 7. C18 works with bytes when it does 1<<count. What is even more peculiar is that temp=1<<11 will place zero in temp not 0x0800 as you would expect.
You can fix the above by doing while((temp&((int)1<<count))==0) or adding -Oi command line option.
So, why am I telling you this. Cause it took me a long time to find it and I just had to get it of my chest. Plus, it may help others.
BTW, the above worked fine in BoostC and it is the C18 compiler that doesn't comply with ISO.
Edit, One good point about C18 is that it's free.
Mike.
and
Sure, add it to that thread. It's not really a bug but can cause some nasty bugs.
Who would have thought that writing,
Code:
unsigned int temp=10*60;
would not be the same as,
Code:
unsigned int temp=600;
I always assumed that constants would be treated as 32 (or even 64) bits on the PC and cast to the appropriate size during assignment.
Ok, the other night I was having some trouble with a program. I kept getting the following error:
Code:
MPLINK 4.40, Linker
Device Database Version 1.3
Copyright (c) 1998-2011 Microchip Technology Inc.
Error - section '.udata_c018i.o' can not fit the section. Section '.udata_c018i.o' length=0x0000000a
Errors : 1
Link step failed.
After trying out a few different options, I figured out that my program was larger than the 256 byte RAM could handle. The way to fix this error (can be different from ".udata_c018i.o"--the fix is the same) is to cut down as much as you can on the code. Get rid of any extra arrays, especially, as they take up a lot of space. Also cut down on your ints as much as possible. This will hopefully allow your program to "fit".
Hey DS8 the other way is to Initialise a few variables... then they are compiled in the idata section as well as the udata section... Microchip didn't figure on folks like us declaring ALL of the variables un-initialised.... There is a couple of banks reserved for both..
Hey DS8 the other way is to Initialise a few variables... then they are compiled in the idata section as well as the udata section... Microchip didn't figure on folks like us declaring ALL of the variables un-initialised.... There is a couple of banks reserved for both..
I think the ram pages are 256 byte in size.. When I last had this problem, the compiler complained about the udata ( basically it can't allocate any more).. When I looked at the memory usage gauge there was loads of ram left.. That's when I did the investigation. There was about 170 bytes of idata free. Ta da!!
When you step through the code with a PICkit2 SFR TMR0H can not be written to. If you run it works. The chip in this example is the PIC18F330 but I it should exist in other PICs with the same TIMER0 hardware. You will not see it using MPLAB SIM.
Code:
T0CONbits.TMR0ON = 1; // start timer0
while(1)
{
Nop();
Nop();
Nop();
TMR0H = h++; // if you step these 2 lines it does not work
TMR0L = l++;
result = TMR0L;
result += ((unsigned int) TMR0H)<<8;
Nop(); // set BP here
Nop();
Nop();
TMR0H = 0x00; // if you step these 2 lines it does not work
TMR0L = 0x00;
result0 = TMR0L;
result0 += ((unsigned int) TMR0H)<<8;
}
}
When you step and monitor the register it won't work. Try stepping without monitoring them and it should work. This is due to the fact that TMR0H is not a real register but a buffer register and so after the write to TMR0H the update will latch the existing value of the real TIMER0H. See 11.4 in the data sheet for an explanation.
I was going to post that 0x05 doesn't work on that chip It should be 0x07
But I had to look to make sure who ever wrote the data sheet may of wrote one that did use 0x05 at the same time.
Cant trust them data sheets LOL
This is from the PIC16(L)F1826/27 data sheet.
They say just copy and paste
;This code block configures the ADC
;for polling, Vdd and Vss references, Frc
;clock and AN0 input.
;Conversion start & polling for completion
; are included.
BANKSEL ADCON1 ;
MOVLW B’11110000’ ;Right justify, Frc clock
MOVWF ADCON1 ;Vdd and Vss Vref
BANKSEL TRISA ;
BSF TRISA,0 ;Set RA0 to input
BANKSEL ANSEL ;
BSF ANSEL,0 ;Set RA0 to analog
On build it said ANSEL is undefined. That's because the 16F1827 has ADC on PORTB as well. So you need to use ANSELA and ANSELB. I found those in the 16F1827.inc file.
I am also finding a snag using code for one chip on a different chip.
If the compiler complains about things being undefined, check the .inc or .h files for that chip. Just lately I found these varieties and a couple more for the ADC.