Compiler/TMS320F28379D: Byte Packing awaylable today?

Marcel,

As far as I am aware byte packing is still not supported by the C28x C compiler.  However, the assembly instruction set does support limited byte operations on the accumulator, so you can do this if you work in assembly.

I am not sure if this will help you, but the attached file contains two assembly functions to pack and un-pack four bytes into a 32-bit long.  It makes use of a struct to hold the bytes.  The C prototypes would be something like...

typedef volatile struct {

   char b0;

   char b1;

   char b2;

   char b3;

} BYTE_PACK;

BYTE_PACK lbp;

long lx, ly;

extern long byte_pack(BYTE_PACK *s);

extern BYTE_PACK byte_unpack(long x);

...then in your code...

   lbp.b0 = 0x3F;

   lbp.b1 = 0x0C;

   lbp.b2 = 0x16;

   lbp.b3 = 0x9E;

   lx = byte_pack(&lbp);

   ly = 0x12345678;

   lbp = byte_unpack(ly);

This is just an example and I have not tested it extensively.  You may be able to modify it if you have something specific you want to do. 

Others on the forum may have other suggestions.  Anyway, I hope it helps.

Regards,

Richard

demo2806x_byte.asm