Error 71 Out of ROM problem

[silelis]

Hello,

I am developing some code. Before small part of code is like below:

[jeremiah]

You most likely have a function that is too large to fit into a page of memory. Break up your bigger functions into smaller ones.

[silelis]

How to recognize which function.

Wkat does this data exactly means:

[jeremiah]

Try disabling your logging and see if that lets it compile. If so, it is one of the functions with your logging. My gut tells me it is the one with the case statements, but I don't know what other code you have.

[temtronic]

this....
Seg 00058-007FF, 02A5 left, need 00760

means
your program needs 760 memory locations but the segment from 0058 to 7ff only has 2A5 spaces left, so the compiler can't put 760 where only 2A5 are.

The same is true for the other 'segments' of memory.

You need to 'breakup' or 'reorganise' some of your code to make it fit. Sometimes putting your 'functions' in a different order will help depending on how smart the compiler version you have. other times taking a 'large' function and breaking it into 2 or more 'sub functions' will allow the program to compile.

It's just the way the 877 was designed 20+ years ago, memory is in 'banks' or 'segments'. Today, the 'new' PICS have huge, contiguous memory,so 'creative coding' isn't required.

Jay

[Ttelmah]

I'm guessing he is using the USB PIC16 he is talking about in another thread?.
If so the physical page size is 0x800 (0 to 7FF). He has one code routine wanting 0x8A0, so this is never going to fit. The 0x760 one, is presumably interrupt handling, or his main, which the compiler needs to put in the bottom page. The USB code already nearly fills the bottom page on these chips, so it is vital when adding your own code to the demo, to put this as subroutines that can then be moved into later pages.
This is the problem of the PIC16 architecture versus the PIC18. Though there are limitations on the PIC18 for some things, for most code these chips are 'pageless'.
A search here will find dozens of threads about this error, and a read of some will explain what has to be done. Jeremiah's comment is basically a summary of what has to happen.
You need to think in term of structuring the code in little pieces, not as monolithic lumps.

[PCM programmer]

Also, your code is not written in the most efficient way. I was able to
reduce the ROM usage for the following test program from initially 411
words down to 317 words.

First, I noticed you are disabling/enabling ints when you do an fprintf. So
you're probably using a software UART. But you can disable ints during
transmission by adding DISABLE_INTS to the #use rs232() statement as
shown in bold below. That allows you to remove all the disable/enable ints
in the routine.

Then, I notice you do delay_ms(500) in every section. Well, why not
get rid of all those individual delays and just put one line at the end ?

I did these changes and saved 94 bytes. Go through your whole
program and re-write it for code efficiency.

[silelis]

I have divided the code and really it helps to avoid the compilation error.

Also I want to thank for DISABLE_INTS idea. It will save my ROM space and saves 5% of ROM. .