Word and Byte Pointers

The alignment requirements explained above determine how the compiler uses DSP56800E byte and word pointers to implement C pointer types. The compiler uses:

• Word pointers for all structures
• The SP to access the stack resident data of all types:
  • Bytes
  • Shorts
  • Longs
  • Floats
  • Doubles
  • Any pointer variables
• Word pointers to access:
  • Shorts
  • Longs
  • Any pointer variables
• Byte pointers for:
  • Single global or static byte variable, if accessed through a pointer using X:(Rn)
  • Global or static array of byte variables

    The compiler does not use pointers to access scalar global or static byte variables directly by their addresses. Instead, it uses an instruction with a .BP suffix:

    MOVE[U].BP   X:xxxx,<dest>
    
    MOVE.BP      <src>,X:xxxx