PCH pointers

[Douglas Richard]

Got the following code for the PCH compiler (18F248):

#define start_node_address 0X200
#define end_node_address 0X2FF

int *node_info;

node_info = start_node_address;

The above code will not compile and I will get this error:

Constant out of the valid range

If I do the following it will compile:

#define start_node_address 0X100
#define end_node_address 0X1FF

OR if I do this it will compile:

int32 *node_info;

long int *node_info; will not compile.

The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).

any thoughts.
___________________________
This message was ported from CCS's old forum
Original Post ID: 8247

[Mark]

:=Got the following code for the PCH compiler (18F248):
:=
:= #define start_node_address 0X200
:= #define end_node_address 0X2FF
:=
:= int *node_info;
:=
:= node_info = start_node_address;
:=
:=The above code will not compile and I will get this error:
:=
:= Constant out of the valid range
:=
:=If I do the following it will compile:
:=
:= #define start_node_address 0X100
:= #define end_node_address 0X1FF
:=
:=OR if I do this it will compile:
:=
:= int32 *node_info;
:=
:=long int *node_info; will not compile.
:=
:=The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).
:=
:=any thoughts.
:=
___________________________
This message was ported from CCS's old forum
Original Post ID: 8249

[Carlos Barberis]

Pointers to constants are not permitted, see pg 51 of CCS manual
:=Got the following code for the PCH compiler (18F248):
:=
:= #define start_node_address 0X200
:= #define end_node_address 0X2FF
:=
:= int *node_info;
:=
:= node_info = start_node_address;
:=
:=The above code will not compile and I will get this error:
:=
:= Constant out of the valid range
:=
:=If I do the following it will compile:
:=
:= #define start_node_address 0X100
:= #define end_node_address 0X1FF
:=
:=OR if I do this it will compile:
:=
:= int32 *node_info;
:=
:=long int *node_info; will not compile.
:=
:=The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).
:=
:=any thoughts.
:=
___________________________
This message was ported from CCS's old forum
Original Post ID: 8251

[Mark]

He is not doing a pointer to a constant.
A pointer to a constant would be something like this:

char const mystring[6]={"Hello"}
ptr = mystring;

He is only assigning an address.

Regards,
Mark

:=Pointers to constants are not permitted, see pg 51 of CCS manual
:=:=Got the following code for the PCH compiler (18F248):
:=:=
:=:= #define start_node_address 0X200
:=:= #define end_node_address 0X2FF
:=:=
:=:= int *node_info;
:=:=
:=:= node_info = start_node_address;
:=:=
:=:=The above code will not compile and I will get this error:
:=:=
:=:= Constant out of the valid range
:=:=
:=:=If I do the following it will compile:
:=:=
:=:= #define start_node_address 0X100
:=:= #define end_node_address 0X1FF
:=:=
:=:=OR if I do this it will compile:
:=:=
:=:= int32 *node_info;
:=:=
:=:=long int *node_info; will not compile.
:=:=
:=:=The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).
:=:=
:=:=any thoughts.
:=:=
___________________________
This message was ported from CCS's old forum
Original Post ID: 8255

[R.J.Hamlett]

:=Got the following code for the PCH compiler (18F248):
:=
:= #define start_node_address 0X200
:= #define end_node_address 0X2FF
:=
:= int *node_info;
:=
:= node_info = start_node_address;
:=
:=The above code will not compile and I will get this error:
:=
:= Constant out of the valid range
:=
:=If I do the following it will compile:
:=
:= #define start_node_address 0X100
:= #define end_node_address 0X1FF
:=
:=OR if I do this it will compile:
:=
:= int32 *node_info;
:=
:=long int *node_info; will not compile.
:=
:=The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).
:=
:=any thoughts.
:=
You don't say which compiler version. I suspect this is a version of a fault I had with the CCS compiler, which has now (largely) been fixed, where if I generated pointers to an integer, I found the compiler generating 8 bit pointers. However if I generated pointers to int16 values, it used a 16bit pointer, and if I went to using pointers to int32 values it used 32bit pointers!.
This was fixed a while ago, but when I ran into this problem, I found the fault only affected certain pointer operations, so I could 'code round' the problem, by declaring my pointers to be to a larger data type, and then casting the resulting pointer to the right type in use.
So something like:

int32 *node_info;
node_info=start_node_address;

Then when I wanted to use the pointer, employing:

val=(int *)start_node_address;

The only problem with this, is that address arithmetic, then doesn't follow the normal rules...

Best Wishes
___________________________
This message was ported from CCS's old forum
Original Post ID: 8267

[Mark]

I know I typed a response but here is what I found.

The compiler would not allow a value greater than 0x1FF.
However this works great

#byte start_node = 0x200
#define start_node_address &start_node
#define end_node_address &start_node + 0xFF
int *node_info;

node_info = start_node_address;


:=:=Got the following code for the PCH compiler (18F248):
:=:=
:=:= #define start_node_address 0X200
:=:= #define end_node_address 0X2FF
:=:=
:=:= int *node_info;
:=:=
:=:= node_info = start_node_address;
:=:=
:=:=The above code will not compile and I will get this error:
:=:=
:=:= Constant out of the valid range
:=:=
:=:=If I do the following it will compile:
:=:=
:=:= #define start_node_address 0X100
:=:= #define end_node_address 0X1FF
:=:=
:=:=OR if I do this it will compile:
:=:=
:=:= int32 *node_info;
:=:=
:=:=long int *node_info; will not compile.
:=:=
:=:=The above solutions are no solutions at all. I want to use the memory from 200 to 2FF and I believe int32 *node_info will give me a pointer to a double (instead of an interger).
:=:=
:=:=any thoughts.
:=:=
___________________________
This message was ported from CCS's old forum
Original Post ID: 8268