《基于TI DSP的通用算法实现》程序代码

				
				
				; Example 6 - 11. SSLMS Implementation ASM Listing for the TMS320C2x DSP
				
				               .title     'TSE25'
				
				*************************************************************
				*
				*    TSE25 : Adaptive Filter Using Transversal Structure
				*           and Sign-Sign LMS Algorithm, Looped Code
				*
				*    Algorithm:
				*
				*             63
				*       y(n) = SUM w(k)*x(n-k)    k=0,1,2,…,63
				*             k=0
				*
				*       e(n) = d(n) – y(n)
				*
				*       For k = 0,1,2,…,63
				*            w(k) = w(k) + u  if e(n)*x(n-k) >= 0
				*            w(k) = w(k) - u  if e(n)*x(n-k) < 0
				*
				*        Where we use filter order = 64 and mu = 0.01
				*
				*   Note: This source program is the generic version; I/O configuration has
				*        not been set up. User has to modify the main routine for specific
				*        application
				*
				*     Initial condition:
				*        1) PM status bit should be equal to 01.
				*        2) SXM status bit should be set to 1.
				*        3) The current DP (data memory page pointer) should be page 0.
				*        4) Data memory ONE should be 1.
				*        5) Data memory U should be 327.
				*
				*                     Chen,Chein-Chung   February, 1989
				*
				***************************************************************
				
				*
				*     DEFINE PARAMETERS
				*
				
				ORDER:      .equ     64
				PAGEO:      .equ      0
				
				*
				*     DEFINE ADDRESSES OF BUFFER AND COEFFICIENTS
				*
				
				X0:           .usect          "buffer", ORDER-1
				XN:           .usect          "buffer", 1
				WN:           .usect          "coeffs", ORDER
				
				*
				*    RESERVE  ADDRESSES  FOR  PARAMETERS
				*
				
				D:             .usect            "parameters",1
				Y:             .usect            "parameters",1
				ERR:           .usect            "parameters",1
				ONE:           .usect            "parameters",1
				U:             .usect            "parameters",1
				ERRF:          .usect            "parameters",1
				
				*******************************************************
				*       PERFORM  THE  ADAPTIVE  FILTER
				*******************************************************
				
				                 .text
				*
				*    ESTIMATE  THE  SIGNAL  Y
				*
				
					   LARP          AR3  
				           CNFP                            ; Configure B0 as program memory
				           MPYK         0                  ; Clear the P register
				           LAC          ONE,15             ; Using rounding
				           LRLK         AR3,XN             ; Point to the oldest sample 
				FIR        RPTK         ORDER-1            ; Repeat N times
				           MACD        WN+0fd00h,*-        ; Estimate Y(n)
				           CNFD                            ; Configure B0 as data memory
				           APAC                            
				           SACH         Y                  ; Store the filter output
				
				*
				*   SET  UP  THE  POINTERS
				*
				
				           LARK      AR1,ORDER-1           ; Set up counter
				           LRLK      AR2,WN                ; Point to the coefficients
				           LRLK      AR2,XN+1              ; Point to the data sample
				
				*
				*   CHECK THE SIGN OF ERROR
				*
				            NEG                            
				            ADDH     D                     ; ACC = D(n) – Y(n)
				            SACH     ERR
				
				*
				*    UPDATE  THE  WEIGHTS
				*
				
				ADAPT      LAC          *-,0,AR2      ; ACC = X(n-k)
				           XOR          ERR           ; Get the sign of ERR(n) * X(n-k)
				           SACL         ERRF          ; Store the sign
				           LAC          ERRF          ; Get the sign with its sign extension
				           XORK         MU,15         ; Get the convergent factor MU or –MU
				           ADD          *,15          ; Update W(k)
				           SACH         *+,1,AR1
				           BANZ         ADAPT,*-,AR3
				* 
				FINISH      .end