Declaring Rom Constants

[Dara Hayes]

Hello
Im new to CCS picc and am using the definition as
given in the FAQ for declaring a few bytes in rom that
I wish to send to an LCD , however the more tables
I add the rom usage stays the same and they all seem
to map in at -009 in the list display
Whats going on , the following compile ok but
dont seem to get into the end result OK

Byte Const TABLE1 [5] = {1,2,3,4,5,0};

Thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 1160

[PCM programmer]

:=I'm new to CCS picc and am using the definition as
:=given in the FAQ for declaring a few bytes in rom that
:=I wish to send to an LCD , however the more tables
:=I add the rom usage stays the same and they all seem
:=to map in at -009 in the list display
:=Whats going on , the following compile ok but
:=dont seem to get into the end result OK
:=
:=Byte Const TABLE1 [5] = {1,2,3,4,5,0};

If you don't access the table with code, the compiler
will not put the table into ROM.
----------
If you only access the table elements individually,
with a numeric array index, the compiler will not put
the table into ROM. Instead, it will create assembly
code that uses the immediate value which corresponds
to the table element. Example:

c = TABLE1[0];

With the above line, you will just see assembly code
which puts the value at index 0 into variable c.
-----------

If you want to see the entire table in ROM when you
look at the .LST file, then you must use a variable
as the array index. Example:

for(i = 0; i < 6; i++)
c = TABLE1[i];

-----------

If you put in identical tables, the compiler is smart
enough to figure that out, and it will only put one table
into ROM.
___________________________
This message was ported from CCS's old forum
Original Post ID: 1161

[John Goss]

This is the way I do it... It may help,

I store character messages in a group of statements like below:

const char SelfTestMsg[] = {"SELF TESTING...."};
const char NormalMsg[] = {"NORMAL OPERATION"};

Then I also have a function that can write one character to the LCD called: WriteXLCD();

All I now have to do is:

printf(WriteXLCD,"\%S",NormalMsg)

Hope this helps,
John Goss






:=Hello
:=Im new to CCS picc and am using the definition as
:=given in the FAQ for declaring a few bytes in rom that
:=I wish to send to an LCD , however the more tables
:=I add the rom usage stays the same and they all seem
:=to map in at -009 in the list display
:=Whats going on , the following compile ok but
:=dont seem to get into the end result OK
:=
:=Byte Const TABLE1 [5] = {1,2,3,4,5,0};
:=
:=Thanks
___________________________
This message was ported from CCS's old forum
Original Post ID: 1162

[Dara Hayes]

John ,
that seems to do the trick
many thanks
Dara Hayes
___________________________
This message was ported from CCS's old forum
Original Post ID: 1207