ds2

Capsim Block Documentation

Short Description

This star is a self-contained second order delta sigma modulator.

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Input Connections
Port Type Name
0 float in
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Parameters
Num Description Type Name Default Value
0 The gain of the first integrator float g1 1.0
1 The gain of the second integrator float g2 1.0
2 Binary Quantizer Level float delta 1.0
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States
Num Type Name Initial Value Description
0 float y 1.0
1 float x 0.0
2 float p 0.0
3 float xold 0.0
4 float yold 0.0
5 int numberOutputBuffers
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Declarations


 

	int i;
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Initialization Code



 

       /* note and store the number of output buffers */
        if((numberOutputBuffers = NO_OUTPUT_BUFFERS() ) <= 0) {
                fprintf(stderr,"ds2: no output buffers\n");
                return(1); /* no output buffers */
        }
        if(numberOutputBuffers > 2) {
                fprintf(stderr,"ds2: more than two outputs\n");
                return(2);
        }
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Main Code



 

while(IT_IN(0))
{

	x = xold + g1*in(0) - g1*p;

	y = yold + g2*xold - g2*p;

	p = delta;
	if(y < 0.0) p = -delta;

	
	if(numberOutputBuffers==1) {
		if(IT_OUT(0)) {
			KrnOverflow("ds2",0);
			return(99);
		}
		OUTF(0,0)=p;
	} else {
		if(IT_OUT(0)) {
			KrnOverflow("ds2",0);
			return(99);
		}
		OUTF(0,0)=p;
		if(IT_OUT(1)) {
			KrnOverflow("ds2",1);
			return(99);
		}
		OUTF(0,0)=y;

	}


	xold = x;
	yold = y;
	
}
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Wrapup Code
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License



/*  Capsim (r) Text Mode Kernel (TMK) Star Library (Blocks)
    Copyright (C) 1989-2017  Silicon DSP Corporation

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    http://www.silicondsp.com
    Silicon DSP  Corporation
    Las Vegas, Nevada
*/
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Description



 

/***************************************************************************
		ds2.s
****************************************************************************
This star is a self-contained second order delta sigma modulator.  Ouput 0
is the output of the circuit. Output 1 is the input to the comparator
if connected.
-Parameter one: the gain of the first integrator
-Parameter two: the gain of the second integrator
-Parameter three: the value for delta

ds2


his star is a self-contained second order delta sigma modulator.  Ouput 0
is the output of the circuit. Output 1 is the input to the comparator
if connected.
-Parameter one: the gain of the first integrator
-Parameter two: the gain of the second integrator
-Parameter three: the value for delta


Programmer:	John T. Stonick
Date:		February 1989
Modified: Sasan Ardalan, If a second buffer is added then the 
error prior to 1 bit quantization is output on buffer 1.

*/