Hi All, Am trying to re-write a code in PLM51 to embedded C. There is a statement in PLM51 as below.
DECLARE TASK(17) STRUCTURE(PNTR BYTE,STATUS BYTE,DELAY WORD); DECLARE DELAY_HEAD BYTE AT (.TASK(0).PNTR); //ERROR LINE//
What i have understood from this is-- DELAY_HEAD is a byte variable which resides at the same location as that of TASK(0).PNTR.(From the PLM51 manual)
I have rewritten the same into C as below.
struct tsk { unsigned char PNTR ; unsigned char STATUS; unsigned int DELAY; }TASK[17]; unsigned char DELAY_HEAD _at_ &TASK[0].PNTR ;
But its giving error 221:non-constant case/dim expression. Plss help..!!
Hi, I have solved the checksum error for now.. I have changed the memory model to large in the options of the compiler. My code for that part is now as given here.
unsigned char code MEM_VAL; unsigned int idata *MEM_PTR = &MEM_VAL; /*Warning 259:-Diff pointer mspace */ unsigned int idata CHECK; unsigned int code CONTROL1 = 0xFFFF; for(MEM_PTR=0x0000;MEM_PTR<=0x7FFD;MEM_PTR++) { CHECK=CHECK+MEM_VAL; PCON=0x10; T3=0x0DF; } CHECK=CHECK+0x0FF+0x0FF; if(CHECK!=CONTROL1) { INITIAL_ERROR=90; }
and then selected the linker as BL51 in options and gave a statement as below in the "BL51 Locate".
CODE(?CO?CONTROL1(07FFEh))
As of now there are no errors except for the warning mentioned above.I am trying to remove the warning now. Thanks.
First off - you don't need to change memory model just to get a large pointer.
Secondly, the processor have multiple memory regions - each memory region requires specific instructions to access the data. MEM_VAL is specified "code". Where in your code do you think you instruct the compiler that MEM_PTR is expected to point into the "code" memory region?
What do you think happens when the compiler looks at the type of pointer, and inserts assembler instructions accessing one memory area while the intended values are actually in a compiletely different memory area.
data, idata, code, xdata, pdata really are important for you to understand. Actually vital to understand. Because address 0 in one of these memory regions is a different memory cell compared to address 0 in another memory region.
Indeed - these are absolutely fundamental to any use of any 8051-derivative!
"address 0 in one of these memory regions is a different memory cell compared to address 0 in another memory region"
There are a few cases where the regions overlap - it is left as an exercise for the student to think about which these may be.
It is also possible for the external hardware interface to make (some of) the external memory ranges overlap...
"It is also possible for the external hardware interface to make (some of) the external memory ranges overlap..."
Yes, sometimes xdata may for example be aliased with code for IAP support. And sometimes to allow the processor to download and run code from RAM. But knowing about the different memory regions and checking the datasheet to see if a specific chip have any optional extras is absolutely vital.
Indeed - quite so!
"and checking the datasheet to see if a specific chip have any optional extras"
Of course.
Hey, Thankyou for all the help so far. I have compiled my code and now... Its showing...
compiling ****.c linking... ****.obj To **** RAMSIZE(256) CODE (?CO?CONTROL1(0x7FFE)) WARNING L16 WARNING L16 ERROR L110 RESTRICTED VERSION WITH 0800H BYTE CODE SIZE LIMIT;USED:3014H BYTE LINK/LOCATE RUN COMPLETE.2WARNINGS,1ERROR(S)
Then there is one more fatal error shown in the end.
FATAL ERROR L250:CODE SIZE IN RESTRICTED VERSION EXCEEDED
I am using the student version of KEIL.So are these errors and warnings due the size limit issue?or some other problem???Because i cannot convert this code to a HEX file this way.
Thanks.
RESTRICTED VERSION WITH 0800H BYTE CODE SIZE LIMIT; USED:3014H BYTE
It tells you that you have a 0800H-byte limit, and have used 3014H bytes - in what way is that not clear?
Again, it tells you that you have a restricted version, and you have exceeded the limit.
Hey, Now i have tried the code with the full version and hence the problem is solved. But the 2 warnings and 1 error still remains.
Warning L16 Uncalled Segment, Ignored for Overlay Process ?CO?CONTROL1 Error L110 Cannot Find Segment ?CO?CONTROL1
What is the reason for such an error..??Pls guide me.
Thanks
Uncalled Segment, Ignored for Overlay Process
Isn't that obvious?
Have you checked in your source code - do you think that it should be called from somewhere?
The C51 manual explains the segment naming conventions - so you can relate the segment name reported by the linker to your source code...
Hey,
I have to initialise a variable called CONTROL1 in code memory and locate the same in fixed address 0x7FFE.I have gone through many forums and the Keil user's guide.I have written as below.
unsigned int code CONTROL1 = 0xFFFF;
Then,To use the linker BL51, I have done it as below.
Options->(Am using BL51)BL51 locate->Code ?CO?CONTROL1(07FFEh)
Still the error is L110:Cannot find segment. Apart from the warning mentioned above. The functions mentioned in the warning are called in the program.I have gone through the source code. Pls help Thanks.
But is any part of the program accessing the variable CONTROL1?
Hi, I also want mention that i am using 80552 microcontroller.I want to know if the linker to be used is specific to different microcontrollers.Is it correct to use BL51 for 80552?? Thanks.
Hey, CONTROL1 is a variable used in one of the functions which would be called in the main loop in the initialisation stage.It is used in the Checksum function.The microcontroller used here is 80552 which is a ROMless version and hence using external EEPROM. Thanks.
"CONTROL1 is a variable used in one of the functions which would be called in the main loop"
Why do you say, "would be" there?
Is it called, or isn't it??
Hey, Yes,The function(Named as test_hardw) is called in the main loop..!But CONTROL1 is a local variable inside the function,test_hardw.I dont know if that makes a difference. CONTROL1 takes the value 0xFFFF and has to be located in code memory location 0x7FFE.
Still the error is L110:Cannot find segment.
And you still haven't checked the obvious: do you have a segment by that name? Look into your map file (perhaps after temporarily removing that special linker directive).
If you do have such a segment: is that the one your variable is actually in?