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Hello, After two years of happy working with the keil C166/C167 compiler I've just ran into a problem I don't understand / can't solve. Running phytec kitcon 167 Memory model Hlarge Declared two unsigned long variables :
unsigned long v1; unsigned long v2;
if (v1!=0) { v2 := v1; ..... ..... }
MOV R6,DPP2:0x1750 MOV R7,DPP2:0x1752 MOV R4,R6 OR R4,R7 JMPR CC_Z,0x003A3C MOV DPP2,0x1776,R6 MOV DPP2,0x1778,R7
if (v1!=0)
v2:=v1
Hi Andy, I confirm your statement about running/testing a program with a lot of isr's. For my project I used to drive all isr's with independent signal generators on their input pins. All the measurement data is then transmitted through the serial port. All is received by a windows program that performs all kind of validation on the data. If errors are found they are logged by the program. Running these kind of tests during the night gives you valuable data about the system. This way I also spotted my problem at first. Sure the method does not guarantee that the program is flawless but it has worked fine for me. Thanks for your comment
"For my project I used to drive all isr's with independent signal generators on their input pins." Yep, that's a good stress test, but my point still stands: the fact that you didn't detect any problems does not guarantee that there are no problems. eg, i had a problem a while back where a certain event was occasionally mis-handled. To capture the behaviour, I connected up all the logging stuff like you, and increased the event rate in the hope that the error would manifest more often. It didn't; in fact, it totally stopped happening! It eventually turned out to be an interaction with a background activity lasting 20 seconds or so, and occurring only when the system had been "idle" for 5 minutes or so - so increasing the event rate actually stopped the problem from manifesting! Heisenberg strikes again! I'm not trying to say that testing is worthless; just pointing out that statements like "It's been working for xx months without a problem" are not sufficient to conclude that there are no bugs still lurking!
Problem is solved ! Declaring the variables :
unsigned long volatile v1; unsigned long volatile v2;
/* note: variables that are modified in interrupts are volatile! */