www.pudn.com > g729Decoder.rar > syn_ap1.asm

;===================================================== 
; File Name 
; ------------- 
; syn_ap1.asm 
; 
; Bridf Description of the Code: 
; ------------------------------- 
; Compute the coefficients of synthese filter 
; 
; Ref 
; --------- 
; COD_LD8A.C 
;====================================================== 
        .mmregs 
        .include  ../include/const.h 
        .include  ../include/tab_ld8a.h 
        .include  ../include/ld8amem.h 
 
        .text 
        .def      Syn_ap1 
 
;------------------------------------------------------ 
; Syn_ap1 
;------------------------------------------------------ 
; ap = Ap_t 
; ap1[i] = Ap[i] - 0.7 * Ap[i-1]  i = 1 --> M 
;------------------------------------------------------ 
;  Points : ptr_bi --> Ap_t  (i) 
;           ptr_ap1 --> ap1  (o) 
; 
;  Input Registres : BRC = M - 1 
;------------------------------------------------------ 
 
        .asg    "AR3", pBi 
        .asg    "AR4", pAp1 
 
Syn_ap1: 
 
		MVDM ptr_bi,AR2 
        ST      #4096, *pBi+ 
        ST      #4096, *pAp1+ 
        ST      #22938, *AR2 
 
        RPTB    EndSyn_ap1 - 1 
 
                LD     *AR3-, 16, B 
                ADD     #1, 15, B                ;rounting 
                LD      *AR3, 16, A 
                BC      L0, AEQ 
                MAS     *AR2, *AR3, B 
                ADD     #1, 15, B                ;rounting 
                SAT     B 
L0:             STL     B, -16, *pAp1+ 
                MAR     *+AR3(2) 
EndSyn_ap1: 
 
        RET