197 lines
8.2 KiB
NASM
197 lines
8.2 KiB
NASM
|
;;#############################################################################
|
||
|
|
;;! \file source/fir32.asm
|
||
|
|
;;!
|
||
|
|
;;! \brief 32-bit FIR filter
|
||
|
|
;;!
|
||
|
|
;;! \date Jan 11, 2011
|
||
|
|
;;!
|
||
|
|
;;
|
||
|
|
;;#############################################################################
|
||
|
|
;;!
|
||
|
|
;;! Copyright: Copyright (C) 2023 Texas Instruments Incorporated -
|
||
|
|
;;! All rights reserved not granted herein.
|
||
|
|
;;! Limited License.
|
||
|
|
;;!
|
||
|
|
;;! Texas Instruments Incorporated grants a world-wide, royalty-free,
|
||
|
|
;;! non-exclusive license under copyrights and patents it now or hereafter
|
||
|
|
;;! owns or controls to make, have made, use, import, offer to sell and sell
|
||
|
|
;;! ("Utilize") this software subject to the terms herein. With respect to the
|
||
|
|
;;! foregoing patent license, such license is granted solely to the extent that
|
||
|
|
;;! any such patent is necessary to Utilize the software alone. The patent
|
||
|
|
;;! license shall not apply to any combinations which include this software,
|
||
|
|
;;! other than combinations with devices manufactured by or for TI
|
||
|
|
;;! ("TI Devices").
|
||
|
|
;;! No hardware patent is licensed hereunder.
|
||
|
|
;;!
|
||
|
|
;;! Redistributions must preserve existing copyright notices and reproduce this
|
||
|
|
;;! license (including the above copyright notice and the disclaimer and
|
||
|
|
;;! (if applicable) source code license limitations below) in the documentation
|
||
|
|
;;! and/or other materials provided with the distribution.
|
||
|
|
;;!
|
||
|
|
;;! Redistribution and use in binary form, without modification, are permitted
|
||
|
|
;;! provided that the following conditions are met:
|
||
|
|
;;!
|
||
|
|
;;! * No reverse engineering, decompilation, or disassembly of this software is
|
||
|
|
;;! permitted with respect to any software provided in binary form.
|
||
|
|
;;! * Any redistribution and use are licensed by TI for use only
|
||
|
|
;;! with TI Devices.
|
||
|
|
;;! * Nothing shall obligate TI to provide you with source code for the
|
||
|
|
;;! software licensed and provided to you in object code.
|
||
|
|
;;!
|
||
|
|
;;! If software source code is provided to you, modification and redistribution
|
||
|
|
;;! of the source code are permitted provided that the following conditions
|
||
|
|
;;! are met:
|
||
|
|
;;!
|
||
|
|
;;! * any redistribution and use of the source code, including any resulting
|
||
|
|
;;! derivative works, are licensed by TI for use only with TI Devices.
|
||
|
|
;;! * any redistribution and use of any object code compiled from the source
|
||
|
|
;;! code and any resulting derivative works, are licensed by TI for use
|
||
|
|
;;! only with TI Devices.
|
||
|
|
;;!
|
||
|
|
;;! Neither the name of Texas Instruments Incorporated nor the names of its
|
||
|
|
;;! suppliers may be used to endorse or promote products derived from this
|
||
|
|
;;! software without specific prior written permission.
|
||
|
|
;;#############################################################################
|
||
|
|
;;
|
||
|
|
;;*****************************************************************************
|
||
|
|
;; includes
|
||
|
|
;;*****************************************************************************
|
||
|
|
;;
|
||
|
|
;;*****************************************************************************
|
||
|
|
;; globals
|
||
|
|
;;*****************************************************************************
|
||
|
|
; Module definition for external reference
|
||
|
|
|
||
|
|
.if __TI_EABI__
|
||
|
|
.asg FIR32_init, _FIR32_init
|
||
|
|
.asg FIR32_calc, _FIR32_calc
|
||
|
|
.endif
|
||
|
|
|
||
|
|
.def _FIR32_init
|
||
|
|
.def _FIR32_calc
|
||
|
|
;;
|
||
|
|
;;=============================================================================
|
||
|
|
;; Routine Type : C Callable
|
||
|
|
;; Description :
|
||
|
|
;; void FIR16_calc(FIR16_handle)
|
||
|
|
;;
|
||
|
|
;; This routine implements the non-recursive difference equation of an
|
||
|
|
;; all-zero filter(FIR), of order N. All the coefficients of all-zero
|
||
|
|
;; filter are assumed to be less than 1 in magnitude.
|
||
|
|
;;=============================================================================
|
||
|
|
;;
|
||
|
|
;; Difference Equation :
|
||
|
|
;;
|
||
|
|
;; y(n)=H(0)*x(n)+H(1)*x(n-1)+H(2)*x(n-2)+....+H(N)*x(n-N)
|
||
|
|
;;
|
||
|
|
;; where
|
||
|
|
;; y(n)=output sample of the filter at index n
|
||
|
|
;; x(n)=input sample of the filter at index n
|
||
|
|
;;
|
||
|
|
;; Transfer Function :
|
||
|
|
;;
|
||
|
|
;; Y(z) -1 -2 -N+1 -N
|
||
|
|
;; ----- = h(0) + h(1) z + h(2) z + ... +h(N-1) z + h(N) z
|
||
|
|
;; X(z)
|
||
|
|
;;
|
||
|
|
;; Network Diagram :
|
||
|
|
;
|
||
|
|
;; dbuffer[0] dbuffer[1] dbuffer[2] dbuffer[N}
|
||
|
|
;; Input -1 x(n-1) -1 x(n-2) x(n-N)
|
||
|
|
;; x(n) >------o----z---->-o----z---->-o--- - ->- - o
|
||
|
|
;; | | | |
|
||
|
|
;; | | | |
|
||
|
|
;; | | | |
|
||
|
|
;; v H(0) v H(1) v H(2) v H(N)
|
||
|
|
;; | | | |
|
||
|
|
;; | | | | output
|
||
|
|
;; |---->-----(+)---->----(+)-- - -> - (+)-----> y(n)
|
||
|
|
;;
|
||
|
|
;; Symbols Used :
|
||
|
|
;; H(0),H(1),H(2),...,H(N) : filter coefficients
|
||
|
|
;; x(n-1),x(n-2),...,x(n-N) : filter states
|
||
|
|
;; x(n) : filter input
|
||
|
|
;; y(n) : filter output
|
||
|
|
;;=============================================================================
|
||
|
|
;; Function Input: This function accepts the handle of the below structure
|
||
|
|
;;
|
||
|
|
;; typedef struct { <------------ XAR4
|
||
|
|
;; int32_t *coeff_ptr; /* +0 Pointer to Filter coefficient */
|
||
|
|
;; int32_t * dbuffer_ptr; /* +2 Delay buffer ptr */
|
||
|
|
;; int16_t cbindex; /* +4 Circular Buffer Index */
|
||
|
|
;; int16_t order; /* +5 Order of the Filter */
|
||
|
|
;; int16_t input; /* +6 Latest Input sample */
|
||
|
|
;; int16_t output; /* +7 Filter Output */
|
||
|
|
;; void (*init)(void *); /* +8 Ptr to Init funtion */
|
||
|
|
;; void (*calc)(void *); /* +10 Ptr to calc fn */
|
||
|
|
;; }FIR32;
|
||
|
|
;;
|
||
|
|
|
||
|
|
_FIR32_init:
|
||
|
|
ADDB XAR4,#2
|
||
|
|
MOV *+XAR4[4],#0 ; XAR4->ouput, input=0
|
||
|
|
MOV *+XAR4[6],#0 ; output=0
|
||
|
|
|
||
|
|
MOVL XAR6,*XAR4 ; XAR6=dbuffer_ptr
|
||
|
|
MOV ACC,*+XAR4[3] << 1 ; AL=2*order
|
||
|
|
MOV AH,AL ; AH=2*order
|
||
|
|
ADDB AL,#1 ; AL=2*order+1
|
||
|
|
MOV *+XAR4[2],AH ; cbindex = 2*order (will wrap around if offset > 2*order)
|
||
|
|
|
||
|
|
RPT AL
|
||
|
|
|| MOV *XAR6++,#0
|
||
|
|
|
||
|
|
LRETR
|
||
|
|
|
||
|
|
ConstTable:
|
||
|
|
PosSatVal: .long 0x00FFFFFF ; Corresponds to >> 6
|
||
|
|
NegSatVal: .long 0xFF000000 ; Corresponds to >> 6
|
||
|
|
|
||
|
|
FILTER_SIZE .set 44
|
||
|
|
|
||
|
|
_FIR32_calc:
|
||
|
|
PUSH XAR1 ; Context Save
|
||
|
|
|
||
|
|
SETC SXM,OVM ; AR4=FIR16_handle->coeff_ptr
|
||
|
|
SPM 0 ; Create guard band of >> 6
|
||
|
|
|
||
|
|
MOVL XAR7,*XAR4 ; XAR4->coeff_ptr, XAR7=coeff_ptr
|
||
|
|
MOVZ AR1,*+XAR4[4] ; XAR4->coeff_ptr, AR1=cbindex
|
||
|
|
|
||
|
|
MOVL XAR6,*+XAR4[2] ; XAR4->coeff_ptr, XAR6=dbuffer_ptr
|
||
|
|
MOVL ACC,*+XAR4[6] ; ACC = X:Input
|
||
|
|
|
||
|
|
MOVL *XAR6%++,ACC ; Store in data array and inc circ address
|
||
|
|
MOVL *+XAR4[2],XAR6 ; XAR4->coeff_ptr, update the dbuffer pointer
|
||
|
|
|
||
|
|
MOV ACC,*+XAR4[5] ; AR0=order
|
||
|
|
MOVZ AR0,AL ; AR0=order
|
||
|
|
|
||
|
|
ZAPA ; Zero the ACC, P registers and OVC counter
|
||
|
|
;; <<VC140828 - debug only
|
||
|
|
;;.asg 0, N
|
||
|
|
;;.loop
|
||
|
|
;;QMACL P,*+XAR6[AR1%++],*XAR7++ ; ACC = ACC + P << PM = ACC + P << 0
|
||
|
|
;; ; P = (signed[*+XAR6[AR1%++]] * signed[*XAR7++]) >> 32
|
||
|
|
;;.eval N + 1, N ; increment N
|
||
|
|
;;.break N = FILTER_SIZE
|
||
|
|
;;.endloop
|
||
|
|
;; VC140828>>
|
||
|
|
RPT AR0
|
||
|
|
|| QMACL P,*XAR6%++,*XAR7++
|
||
|
|
|
||
|
|
ADDL ACC,P ; Add the two sums with shift
|
||
|
|
|
||
|
|
ADDB XAR4,#1
|
||
|
|
MOVL *+XAR4[7],ACC ; Store saturated result (Q30)
|
||
|
|
|
||
|
|
SPM 0
|
||
|
|
|
||
|
|
POP XAR1
|
||
|
|
CLRC OVM
|
||
|
|
LRETR
|
||
|
|
|
||
|
|
;;#############################################################################
|
||
|
|
;; End of File
|
||
|
|
;;#############################################################################
|