ex5p13.asm

用于DSK5416的程序

 
**********************************************************************
*
*  This program computes multiply and accumulate using the MAC
*  instruction
*
*       y(n) = h(0)x(n) + h(1)x(n-1) +h(2)x(n-2)
*
*  where, h(0), h(1), and h(2) are in the data-memory locations
*  starting at h. x(n), x(n-1), and x(n-2) are in data-memory locations
*  starting at x. y(n) is to be saved in location y (low 16 bits) and
*  y + 1 (high 16 bits).
*
***********************************************************************

        .global _c_int00
          
        .data 
        .bss x, 3             
        .bss y, 2

h       .int 10, 20, 30
	
        .text

_c_int00:
        SSBX    SXM                     ; Select sign extension mode
        STM     #x, AR2                 ; Initialize AR2 to point to x(n)
        STM     #h, AR3                 ; Initialize AR3 to point to h(0)
        LD      #0H, A                  ; Initialize result  in A = 0
	
        RPT     #2                      ; Repeat the next operation 3 times
        MAC     *AR2+,*AR3+, A          ; y(n) computed
	
        STM     #y, AR2                 ; Select the location for y(n)
        STL     A, *AR2+                ; Save the low part of y(n)
        STH     A, *AR2+                ; Save the high part of y(n)
        NOP                             ; No operation

     	.end