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malik_123pk
Joined: 24 Jul 2010
Posts: 7
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| FFT library |
 Posted: Sat Jul 24, 2010 6:01 am |
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| is there any FFT library for dspic 30F4013 . |
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bkamen
Joined: 07 Jan 2004
Posts: 1615
Location: Central Illinois, USA
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| Posted: Sun Jul 25, 2010 8:02 am |
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Yes.
Microchip's C30 does -- and is a free download with a 60-day (I think) Eval window with a "lite mode" thereafter that's free.
The docs mention how "some" of the library items are written in C which makes me think that most are ASM...
You can always (try) and convert the functions to CCS PCD, but I don't know what the effort required is. (probably not fun... but possibly easy for some items)
Cheers,
-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D |
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malik_123pk
Joined: 24 Jul 2010
Posts: 7
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| Posted: Mon Jul 26, 2010 12:47 am |
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well it could have been easy if microchip had given the detail of C implementation , which i belive is not given .
and i think no asm code also exist , what can u do then to convert it in to CCS . |
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bkamen
Joined: 07 Jan 2004
Posts: 1615
Location: Central Illinois, USA
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| Posted: Mon Jul 26, 2010 8:24 am |
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I'd have to look deeper to see...
I know for C32 all the source is available..
But again - I only scratched the surface to see if anything DSP was available.
Good luck,
-Ben
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D |
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malik_123pk
Joined: 24 Jul 2010
Posts: 7
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| Posted: Tue Jul 27, 2010 5:08 am |
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I have found the FFT asm which is this file.
(do not know how to upload file , so copying the whole file)
| Code: |
;*********************************************************************
; *
; Software License Agreement *
; *
; The software supplied herewith by Microchip Technology *
; Incorporated (the "Company") for its dsPIC controller *
; is intended and supplied to you, the Company's customer, *
; for use solely and exclusively on Microchip dsPIC *
; products. The software is owned by the Company and/or its *
; supplier, and is protected under applicable copyright laws. All *
; rights are reserved. Any use in violation of the foregoing *
; restrictions may subject the user to criminal sanctions under *
; applicable laws, as well as to civil liability for the breach of *
; the terms and conditions of this license. *
; *
; THIS SOFTWARE IS PROVIDED IN AN "AS IS" CONDITION. NO *
; WARRANTIES, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, *
; BUT NOT LIMITED TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND *
; FITNESS FOR A PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE *
; COMPANY SHALL NOT, IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, *
; INCIDENTAL OR CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER. *
; *
; (c) Copyright 2003 Microchip Technology, All rights reserved. *
;*********************************************************************
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; This Complex DIF FFT implementation expects that the input data is a
; complex vector such that the magnitude of the real and imaginary parts
; of each of its elements is less than 0.5. If greater or equal to this
; value the results could produce saturation.
;
; Also, the program performs an implicit scaling of 1/2 for every stage
; to the intermediate values, so that the output values are scaled by a
; factor of 1/N, with N the length of the FFT.
;
; NOTE: input is expected in natural ordering, while output is produced
; in bit reverse ordering.
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; Local inclusions.
.nolist
.include "dspcommon.inc" ; fractsetup,CORCON
; PSVPAG, COEFFS_IN_DATA,
.list
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.section .libdsp, code
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
; _FFTComplexIP: Complex (in-place) DIF FFT.
;
; Operation:
; F(k) = 1/N*sum_n (f(n)*WN(kn)), WN(kn) = exp[-(j*2*pi*k*n)/N],
;
; n in {0, 1,... , N-1}, and
; k in {0, 1,... , N-1}, with N = 2^m.
;
; Input:
; w0 = number stages in FFT (log2N)
; w1 = ptr to complex source vector (srcCV)
; w2 = ptr to complex twiddle factors (twidFactors)
; w3 = COEFFS_IN_DATA, or memory program page with twiddle factors.
; Return:
; w0 = ptr to source vector (srcCV)
;
; System resources usage:
; {w0..w7} used, not restored
; {w8..w13} saved, used, restored
; AccuA used, not restored
; AccuB used, not restored
; CORCON saved, used, restored
; PSVPAG saved, used, restored (if factors in P memory)
;
; DO and REPEAT instruction usage.
; 2 level DO intruction
; no REPEAT intructions
;
; Program words (24-bit instructions):
; 60
;
; Cycles (including C-function call and return overheads):
;
; transform factors factors
; size in X-mem in P-mem
; -----------------------------------------
; 32-point 1664 1827
; 64-point 3802 4189
; 128-point 8612 9511
; 256-point 19310 21361
; 512-point 42872 47483
;
;............................................................................
; Local equates.
; Commented to avoid IAR assembler problems...
; .equ oTwidd,w3
; .equ pTwidd,w8
; .equ nGrps,w9
; .equ pUpper,w10
; .equ pLower,w11
; .equ groupCntr,w12
; .equ buttCntr,w13
; The symbols have been replaced in the code by the corresponding
; working registers; the comments maintain the symbols for clarity.
.global _FFTComplexIP ; export
_FFTComplexIP:
;............................................................................
; Save working registers.
push.d w8 ; {w8,w9} to TOS
push.d w10 ; {w10,w11} to TOS
push.d w12 ; {w12,w13} to TOS
;............................................................................
; Prepare CORCON for fractional computation.
push CORCON
fractsetup w7
;............................................................................
; Prepare CORCON and PSVPAG for possible access of data
; located in program memory, using the PSV.
push PSVPAG
mov #COEFFS_IN_DATA,w7 ; w7 = COEFFS_IN_DATA
cp w7,w3 ; w7 - w3
bra z,_noPSV ; if w3 = COEFFS_IN_DATA
; no PSV management
; else
psvaccess w7 ; enable PSV bit in CORCON
mov w3,PSVPAG ; load PSVPAG with program
; space page offset
_noPSV:
;............................................................................
push w1 ; save return value (srcCV)
;............................................................................
; FFT proper.
mov #0x1,w9 ; to be shifted...
sl w9,w0,w9 ; w9 = N (1<<log2N)
mov #0x1,w3 ; initialize twidds offset,
; also used as num butterflies
mov w2,w8 ; w8-> WN(0) (real part)
; Preform all k stages, k = 1:log2N.
; NOTE: for first stage, 1 butterfly per twiddle factor (w3 = 1)
; and N/2 groups (w9 = N/2) for factors WN(0), WN(1), ..., WN(N/2-1).
mov w0,w13 ; w13= num stages
; w0 available for reuse
_doStage:
; Perform all butterflies in each stage, grouped per twiddle factor.
; Update counter for groups.
lsr w9,w9 ; w9 = N/(2^k)
sl w9,#2,w12 ; w12= lower offset
; nGrps+sizeof(fractcomplex)
; *2 bytes per element
; Set pointers to upper "leg" of butterfly:
mov w1,w10 ; w10-> srcCV (upper leg)
; Perform all the butterflies in each stage.
dec w3,w4 ; w4 = butterflies per group
do w4,_endBflies ; { ; do 2^(k-1) butterflies
; Set pointer to lower "leg" of butterfly.
add w12,w10,w11 ; w11-> srcCV + lower offset
; (lower leg)
; Prepare offset for twiddle factors.
sl w3,#2,w0 ; oTwidd*sizeof(fractcomplex)
; *2 bytes per element
; Perform each group of butterflies, one for each twiddle factor.
dec w9,w4 ; w4 = nGrps-1
do w4,_endGroup ; { ; do (nGrps-1)+1 times
; no more nested do's...
.ifdef YMEM_ERRATA
nop
.endif
; Butterfly proper.
clr a,[w8]+=2,w6,[w10]+=2,w4 ; a = 0 (for dual fetch only)
; w6 = Wr
; pTwidd-> Wi
; w4 = Ar
; pUpper-> Ai (=Ci)
sub w4,[w11++],w4 ; w4 = Ar - Br
; pLower-> Bi (=Di)
mpy w4*w6,a,[w8]-=2,w7,[w10]-=2,w5 ; a = (Ar - Br)*Wr
; w7 = Wi
; pTwidd-> Wr
; w5 = Ai
; pUpper-> Ar (=Cr)
; Update twiddle pointer.
add w0,w8,w8 ; pTwidd-> for next group
mpy w4*w7,b ; b = (Ar - Br)*Wi
sub w5,[w11--],w5 ; w5 = Ai - Bi
; pLower-> Br (=Dr)
msc w5*w7,a,[w11]+=2,w7 ; a = (Ar - Br)*Wr
; - (Ai - Bi)*Wi = Dr
; w7 = Br
; pLower-> Bi (=Di)
mac w5*w6,b,[w11]-=2,w5 ; b = (Ar - Br)*Wi
; + (Ai - Bi)*Wr = Di
; w5 = Bi
; pLower-> Br (=Dr)
sac.r a,#1,[w11++] ; save 1/2*Dr
; pLower-> Bi (=Di)
sac.r b,#1,[w11++] ; save 1/2*Di
; pLower-> Br (next)
lac [w10++],a ; a = Ar
; pUpper-> Ai (=Ci)
lac [w10--],b ; b = Ai
; pUpper-> Cr
add w7,a ; a = Ar + Br
add w5,b ; b = Ai + Bi
sac.r a,#1,[w10++] ; save 1/2*Cr
; pUpper-> Ci
_endGroup:
sac.r b,#1,[w10++] ; save 1/2*Ci
; pUpper-> Ar (next)
; }
add w12,w10,w10 ; w10-> upper leg (next set)
_endBflies:
mov w2,w8 ; rewind twiddle pointer
; }
; Update offset to factors.
sl w3,w3 ; oTwidd *= 2
; Find out whether to perform another stage...
dec w13,w13 ; w13= log2N - k -1
bra gt,_doStage ; if W13 > 0, do next stage
_endStages: ; else, no more stages...
;............................................................................
pop w0 ; restore return value
;............................................................................
; Restore PSVPAG and CORCON.
pop PSVPAG
pop CORCON
;............................................................................
; Restore working registers.
pop.d w12 ; {w12,w13} from TOS
pop.d w10 ; {w10,w11} from TOS
pop.d w8 ; {w8,w9} from TOS
;............................................................................
return
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.end
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; OEF
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I have to work hard if I have to put port it into CCS.
Implementing FIR filter on CCS was easy but it seems so difficult. |
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malik_123pk
Joined: 24 Jul 2010
Posts: 7
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| Posted: Mon Aug 02, 2010 11:18 pm |
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Can you guys imagine CCS provides the fft routine in it compiler.
I request the CCS administration to highlight this fact. I spent about three weeks in understating and implementing the FFT on MATLAB, I was all set to convert the algo into the Dspic assembly when I found accidentally that FFT function do exist for the CCS compiler.
How good it would have been if this was highlighted in the CCS already, under DSP section.
I request CCS administration that please add a separate DSP section in the content section of CCS HELP. |
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