In SX Microcontrollers, SX/B Compiler and SX-Key Tool, peterverkaik wrote:

The use of const char * parameters in functions, makes cc1b insert small pieces of
runtimecode. I think there is one piece per const * parameter.
_const1
        MOV   ci,W
        MOV   W,ci
        AND   W,#1
        ADD   PCL,W
        RETW  0
        RETW  0
_const2

My library cstring.h has 9 functions, each of which has 1 const char * parameter,
and then 9 pieces of runtime code are inserted.

To overcome this I wrote a library dstring.h (the d in dstring stands for data - from cdata)
that uses long instead of const char *.
#pragma cdata must then be used to store strings in rom.
Example:
//area for storage of constant data (at end of program code)
#define CDATA_START (_CHIP_CODESIZE_ - 0x0100)
#pragma cdata[CDATA_START]
#pragma cdata.LabelName = "Hello world\0"
#pragma cdata.AnotherLabel = "Direct storage\0"
#pragma cdata.Numbers = 0xF00,0xABC,0x0F
#pragma cdata.LabelTable = LabelName,AnotherLabel,Numbers
#pragma cdata.CDATA_END


The define _CHIP_CODESIZE_ has been added to the chip header files.
To get the length of a string in rom you can use
long p = dstrlen(LabelName);
I added 2 functions to memory.h
long RomWord(long addr); //get word (12bits) from rom address
char RomChar(long addr); //get char (8bits) from rom address
I have put the const char * functions now in their own cstring.h library.
(the c in cstring stands for const - from const *)
The file memory_test.c shows a general program layout, including cdata.

regards peter

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