IAR AVR can not support multi dimention array ?

[maziar]

error[pe513]

IAR have problem with two dimension array ?


//////////// start of code

#include <iom16.h>

unsigned char VRAM [2][5];

void main(void)
{
unsigned char * p;
p = VRAM ;
PORTD = * p ;

}

////////////End of code

have generate :

Error[Pe513]: a value of type "unsigned char (*)[5]" cannot be assigned to an entity of type
"unsigned char *"

Errors: 1
Warnings: none



why ? Iar can not support multidimention array true ?

what to do ?

 

[james]

iar avr array

maziar,

VRAM is a two dimension array, so it would be wrong (from stricly ANSI) to assign it entirely to a pointer in such of way.

p = VRAM ;
would not assign to p the address of the element at [row0][col0] as for your intentions.

You should write for instance:

p = VRAM[0];. This would assign to p the address of the first element (row 0) at col 0.

Above wont give any error.

 

[visioneer]

arrays in c assign avr

IAR have problem with two dimension array ?


//////////// start of code

#include <iom16.h>

unsigned char VRAM [2][5];

void main(void)
{
unsigned char * p;
p = VRAM ;
PORTD = * p ;

}

////////////End of code

have generate :

Error[Pe513]: a value of type "unsigned char (*)[5]" cannot be assigned to an entity of type
"unsigned char *"

Errors: 1
Warnings: none



why ? Iar can not support multidimention array true ?

what to do ?

or U can assign VRAM to pointer to pointer like this

unsigned char **p ;

p = VRAM ;



visioneer

 

[maziar]

avr array dimension

i test p = VRAM ;

in ke** ,VC++ , BC++Builder all ok but IAR ...

 

[james]

iar c array multidimensional

It is not at all unusual the situation where some compiler is a bit more "permissive" then others. However it doesn't mean the result is correct even you don't receive back a compiler error. Often a check to the generated object code reveals most of traps.

Please read "Brian W. Kernighan & Dennis M. Ritchie" 2nd edition, chapter 5.7 MULTIDIMENSIONAL VECTORS.

About assigning a pointer to pointer I'm dubtly will work. The main problem here is when you need to pass VRAM [row][col] (to a pointer or as a function parameter) you need to specify [col] dimension except the very first dimension [row] that is free.

 

[C-Man]

avr write array values

This is what PC-Lint tries to tell you:

PC-lint for C/C++ (NT) Ver. 8.00n, Copyright Gimpel Software 1985-2003
--- Module: E:\WINDOWS\Desktop\test.c

--- Module: E:\WINDOWS\Desktop\test.c
_
p = VRAM ;
E:\WINDOWS\Desktop\test.c 6 Error 64: Type mismatch (assignment) (unsigned char * = unsigned char (*)[5])

And here is what Error 64 means:

64 Type mismatch (Context) (TypeDiff)
-- There was a mismatch in types across an
assignment (or implied assignment, see Context). TypeDiff specifies the type difference.
See options -epn, -eps, -epu, -epp (Section 5.2 Error Inhibition Options) to suppress this mes-sage
when assigning some kinds of pointers.

have fun

 

[sky123]

array avr

Hi,

Try the line:
p=(unsigned char *)VRAM;

I think this will compile.


Sky.