16ptdct.dsp

载dsp上实现16dct和8dct的程序

{  ONE DIMENSIONAL, FAST, DISCRETE COSINE TRANSFORM, 16 POINTS
   
   Implementation:
        as described by Hsieh S. Hou in IEEE Transactions on Acoustics, 
        Speech, and Signal Processing, Vol. ASSP-35, No. 10, October 1987

   Target Processor:
        ADSP-2100 family of DSP processors from Analog Devices, Inc.

   Execution Benchmark:
        318 instruction cycles -- ADSP-2101 -- 15.90 us at CLKIN=20.00Mhz

   Memory Storage Requirement:
        272 PM = 257 program memory code, 15 program memory data (coefficients)
        32 DM = 16 data memory scratch pad, 16 data memory (16-pt vector)
        Note: resulting transform coefficients written over original input data
        assumes: unsigned 8-bit input data, signed 16-bit output coefficients

   Author of Code:
        Christoph D. Cavigioli -- DSP Applications Engineer -- [phone]

   Release History:
        27-March-1989, extensively revised: 17-July-1989
        Revised: 23-July-1989
        Revised for ADSP-2101 by Ron Coughlin 28-July-1993

   Analog Devices, Inc., DSP Division, P.O.Box 9106, Norwood, MA 02062, USA
}
.module/ram/abs=0       fast_16pt_dct;
.var/pm/ram             cosvals[15];        { cosine coefficients }
.var/circ/abs=0x3800    tmp[16];            { temporary scratch memory }
.var                    x[16];              { 16pt vector to transform }
.global    tmp;
.external  DIF16, DIF8, DIF4, DIF2, RLR4, RLR8, RLR16, DC_AND_BREV;
.init      x: <fhex.dat>;
.init  cosvals[00]: h#7F6200, h#70E200, h#513300, h#252800,
                    h#F37500, h#C3AA00, h#9D0E00, h#858300;
.init  cosvals[08]: h#7D8A00, h#471C00, h#E70800, h#959300;
.init  cosvals[12]: h#764100, h#CF0500;
.init  cosvals[14]: h#5A8200;

{ interupt vector table }

rest:   jump setup; rti; rti; rti;      { jump here on reset }
        rti; rti; rti; rti;             { irq2 interrupt vector }
        rti; rti; rti; rti;             { sport0 tx interrupt vector }
        rti; rti; rti; rti;             { sport0 rx interrupt vector }
        rti; rti; rti; rti;             { sport1 tx interrupt vector }
        rti; rti; rti; rti;             { sport1 rx interrupt vector }
        rti; rti; rti; rti;             { timer interrupt vector }

setup:  l0=0; l1=0; l2=0; l3=0; l5=0; l6=0;
dct16:  i2=^x; i3=^x+15; i6=^cosvals;
        m2=2; m3=-2; m5=1; m6=1; m7=-3;
        se=1;
        call DIF16;
        call DIF8;
        call DIF4;
        call DIF2;
        call RLR4;
        call RLR8;
        call RLR16;
        i5=^x;
        call DC_AND_BREV;
idwait: idle;
        jump idwait;
.endmod;