/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: Nms1.java
*
* Copyright (c) 2003 Sun Microsystems and Static Free Software
*
* Electric(tm) is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* Electric(tm) 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Electric(tm); see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, Mass 02111-1307, USA.
*/
package com.sun.electric.tool.generator.layout.gates;
import com.sun.electric.database.hierarchy.Cell;
import com.sun.electric.database.prototype.PortCharacteristic;
import com.sun.electric.tool.generator.layout.FoldedMos;
import com.sun.electric.tool.generator.layout.FoldedNmos;
import com.sun.electric.tool.generator.layout.FoldsAndWidth;
import com.sun.electric.tool.generator.layout.LayoutLib;
import com.sun.electric.tool.generator.layout.StdCellParams;
import com.sun.electric.tool.generator.layout.TechType;
import com.sun.electric.tool.generator.layout.TrackRouter;
import com.sun.electric.tool.generator.layout.TrackRouterH;
import com.sun.electric.tool.Job;
public class Nms1 {
private static final double wellOverhangDiff = 6;
private static final double gY = -4.0;
private static final double dY = -11.0;
private static final double nmosTop = -9.0;
// The minimum diffusion surrounding a diffusion contact
// private static final double minContDiff = 5;
private static void error(boolean pred, String msg) {
Job.error(pred, msg);
}
public static Cell makePart(double sz, StdCellParams stdCell) {
TechType tech = stdCell.getTechType();
sz = stdCell.roundSize(sz);
String nm = "nms1" + (stdCell.getDoubleStrapGate() ? "_strap" : "");
sz = stdCell.checkMinStrength(sz, 1, nm);
// Space needed at top of MOS well.
// We need more space if we're double strapping poly.
double outsideSpace = stdCell.getDoubleStrapGate() ? (
2 + 5 + 1.5 // p1_nd_sp + p1m1_wid + p1_p1_sp/2
) : (
wellOverhangDiff
);
double spaceAvail = nmosTop - (stdCell.getCellBot() + outsideSpace);
double totWid = sz * 3;
FoldsAndWidth fw = stdCell.calcFoldsAndWidth(spaceAvail, totWid, 1);
error(fw==null, "can't make Nms1 this small: "+sz);
Cell nms1 = stdCell.findPart(nm, sz);
if (nms1!=null) return nms1;
nms1 = stdCell.newPart(nm, sz);
// leave vertical m1 track for g
double gX = 1.5 + 2; // m1_m1_sp/2 + m1_wid/2
LayoutLib.newExport(nms1, "g", PortCharacteristic.IN, tech.m1(),
4, gX, gY);
// gnd port overlaps leftmost MOS diffusion contacts
double mosX = gX + 2 + 3 + 2; // m1_wid/2 + m1_m1_sp + m1_wid/2
double nmosY = nmosTop - fw.physWid/2;
FoldedMos nmos = new FoldedNmos(mosX, nmosY, fw.nbFolds, 1,
fw.gateWid, nms1, tech);
// output d m1_wid/2 + m1_m1_sp + m1_wid/2
double dX = StdCellParams.getRightDiffX(nmos) + 2 + 3 + 2;
LayoutLib.newExport(nms1, "d", PortCharacteristic.OUT, tech.m1(),
4, dX, dY);
// create gnd export and connect to MOS source/drains
stdCell.wireVddGnd(nmos, StdCellParams.EVEN, nms1);
// connect up input g
TrackRouter g = new TrackRouterH(tech.m1(), 3, gY, tech, nms1);
g.connect(nms1.findExport("g"));
for (int i=0; i<nmos.nbGates(); i++) g.connect(nmos.getGate(i, 'T'));
if (stdCell.getDoubleStrapGate()) {
// Connect gates using metal1 along bottom of cell
double gndBot = stdCell.getGndY() - stdCell.getGndWidth()/2;
double inLoFromGnd = gndBot - 3 - 2; // -m1_m1_sp -m1_wid/2
double nmosBot = nmosY - fw.physWid/2;
double inLoFromMos = nmosBot - 2 - 2.5; // -nd_p1_sp -p1m1_wid/2
double inLoY = Math.min(inLoFromGnd, inLoFromMos);
TrackRouter inLo = new TrackRouterH(tech.m1(), 3, inLoY, tech, nms1);
inLo.connect(nms1.findExport("g"));
for (int i=0; i<nmos.nbGates(); i++) {
inLo.connect(nmos.getGate(i, 'B'));
}
}
// connect up output d
TrackRouter d = new TrackRouterH(tech.m2(), 4, dY, tech, nms1);
d.connect(nms1.findExport("d"));
for (int i=1; i<nmos.nbSrcDrns(); i+=2) {d.connect(nmos.getSrcDrn(i));}
// add wells
double wellMinX = 0;
double wellMaxX = dX + 2 + 1.5; // m1_wid/2 + m1m1_space/2
stdCell.addNmosWell(wellMinX, wellMaxX, nms1);
// add essential bounds
stdCell.addNstackEssentialBounds(wellMinX, wellMaxX, nms1);
// perform Network Consistency Check
stdCell.doNCC(nms1, nm+"{sch}");
return nms1;
}
}