CHANGING THE ORDER OF OBJ FILES MAKES PROGRAM CRASH
Applies to: C51 C Compiler
Information in this article applies to:
Help! I have a problem that causes a routine to not work, but only
at a particular CODE location. If I move the routine to a different
CODE area it will work, move it back and it stops. What's going
There are a few things that you should check.
Make sure that the startup files are the last files in the link
list. The startup code (STARTUP.A51) and the initialization code
(INIT.A51) must be the last 2 files in the link list.
Make sure that any RTX configuration files are at the end of
the link list.
Make sure that you don't have assembly modules (or C modules)
that use ACALL and AJMP instructions that also cross over a 2K-page
boundary. There are 2 types of JMP and CALL instructions in the
8051: LCALL/LJMP and ACALL/AJMP. If you have a program that
exhibits weird behavior just by moving files around, it might be
that you have a module that's compiled for ROM(SMALL) or
ROM(COMPACT) that winds up straddling a 2K page. If that's the
case, the AJMP or ACALL would wind up jumping to the wrong page (2K
before the intended destination). This may be due to an assembly
file or a library routine.
There is a bug in the log and pow floating-point routines in the C51
Version 5.10 library that may cause this problem. The Version 5.11
library update corrects this problem and is available on the Keil web
Article last edited on: 2005-07-15 16:18:24
Rate this article
Disagree? Move your mouse over the bar and click