example3_3.asm

CHP 3 - Real-Time Digital Signal Processing: Implementations and Applications, Second Edition by Sen

; 
;  Project: Example3.3 - Chapter 3
;  File name: example3_3.asm   
;  Function(s): example3_3()
;                
;  Description: This is the assembly routine for example 3.3
;
;  For the book "Real Time Digital Signal Processing: 
;                Implementation and Application, 2nd Ed"
;                By Sen M. Kuo, Bob H. Lee, and Wenshun Tian
;                Publisher: John Wiley and Sons, Ltd
;
;
;  Tools used: CCS v.2.12.07
;              TMS320VC5510 DSK Rev-C
;

	.def _example3_3

    .data 
alpha   .short 0x10 
x1n     .short 0x8
x2n     .short 0x20

	.bss  temp, 1 
	.bss  yn, 1
	
;=========================================================
; Default handler
;=========================================================
	.sect ".text:example"
	
_example3_3
; case 1
    amov  #alpha,XAR1       ; AR1 points to alpha
    amov  #temp,XAR2        ; AR2 points to temp
    amov  #yn,XAR4          ; AR4 points to yn
    mov	  *(x1n),AC0        ; AC0 = x1(n)
    add	  *(x2n),AC0        ; AC0 = x1(n)+x2(n)
    mov   AC0,*AR2          ; temp = x1(n)+x2(n), pointed by AR2
    mpy   *AR1,*AR2,AC1     ; AC1 = alpha*[x1(n)+x2(n)]
    mov   AC1,*AR4          ; yn = alpha*[x1(n)+x2(n)]

; case 2
    amov  #x1n,XAR1         ; AR1 points to x1(n)
    amov  #x2n,XAR2         ; AR2 points to x2(n)
    amov  #alpha,XAR3       ; AR3 points to  
    amov  #yn,XAR4          ; AR4 points to yn
    mpy   *AR1,*AR3,AC1     ; AC1 = alpha*x1(n)
    mac   *AR2,*AR3,AC1     ; AC1 = alpha*x1(n)+alpha*x2(n)
    mov   AC1,*AR4          ; yn = alpha*x1(n)+alpha*x2(n)
    ret
   .end