/* -*- tab-width: 4 -*-
*
* Electric(tm) VLSI Design System
*
* File: InvV.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.FoldedPmos;
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;
/** Separate control over N and P transistor sizes. It's not clear if this is really
* necessary or desireable. I'm doing this for Justin */
public class InvV {
private static final double wellOverhangDiff = 6;
private static final double inY = 0.0;
private static final double outHiY = 11.0;
private static final double outLoY = -11.0;
private static void error(boolean pred, String msg) {
Job.error(pred, msg);
}
public static Cell makePart(double pSz, double nSz, StdCellParams stdCell) {
TechType tech = stdCell.getTechType();
String nm = "invV_p"+pSz+"_n"+nSz+"{lay}";
// Space needed at the top of the PMOS well and bottom 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
);
// find number of folds and width of PMOS
double spaceAvail =
stdCell.getCellTop() - outsideSpace - wellOverhangDiff;
double lamPerSz = 6;
double totWidP = pSz * lamPerSz;
FoldsAndWidth fwP = stdCell.calcFoldsAndWidth(spaceAvail, totWidP, 1);
error(fwP==null, "can't make " + nm + " this small: " + pSz);
// find number of folds and width of NMOS
spaceAvail = -wellOverhangDiff - (stdCell.getCellBot() + outsideSpace);
lamPerSz = 3;
double totWidN = nSz * lamPerSz;
FoldsAndWidth fwN = stdCell.calcFoldsAndWidth(spaceAvail, totWidN, 1);
error(fwN==null, "can't make " + nm + " this small: " + nSz);
// create Inverter Part
Cell inv = stdCell.findPart(nm);
if (inv!=null) return inv;
inv = stdCell.newPart(nm);
// leave vertical m1 track for in
double inX = 1.5 + 2; // m1_m1_sp/2 + m1_wid/2
LayoutLib.newExport(inv, "in", PortCharacteristic.IN, tech.m1(),
4, inX, inY);
double mosX = inX + 2 + 3 + 2; // m1_wid/2 + m1_m1_sp + m1_wid/2
double nmosY = -wellOverhangDiff - fwN.physWid / 2;
FoldedMos nmos = new FoldedNmos(mosX, nmosY, fwN.nbFolds, 1,
fwN.gateWid, inv, tech);
double pmosY = wellOverhangDiff + fwP.physWid / 2;
FoldedMos pmos = new FoldedPmos(mosX, pmosY, fwP.nbFolds, 1,
fwP.gateWid, inv, tech);
// inverter output: m1_wid/2 + m1_m1_sp + m1_wid/2
double outX = StdCellParams.getRightDiffX(nmos, pmos) + 2 + 3 + 2;
LayoutLib.newExport(inv, "out", PortCharacteristic.OUT,
tech.m1(), 4, outX, 0);
// create vdd and gnd exports and connect to MOS source/drains
stdCell.wireVddGnd(nmos, StdCellParams.EVEN, inv);
stdCell.wireVddGnd(pmos, StdCellParams.EVEN, inv);
// Connect up input. Do PMOS gates first because PMOS gate spacing
// is a valid spacing for p1m1 vias even for small strengths.
TrackRouter in = new TrackRouterH(tech.m1(), 3, inY, tech, inv);
in.connect(inv.findExport("in"));
for (int i=0; i<pmos.nbGates(); i++) in.connect(pmos.getGate(i, 'B'));
for (int i=0; i<nmos.nbGates(); i++) in.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 - fwN.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, inv);
inLo.connect(inv.findExport("in"));
for (int i = 0; i < nmos.nbGates(); i++) {
inLo.connect(nmos.getGate(i, 'B'));
}
// Connect gates using metal1 along top of cell
double vddTop = stdCell.getVddY() + stdCell.getVddWidth() / 2;
double inHiFromVdd = vddTop + 3 + 2; // +m1_m1_sp + m1_wid/2
double pmosTop = pmosY + fwP.physWid / 2;
double inHiFromMos = pmosTop + 2 + 2.5; // +pd_p1_sp + p1m1_wid/2
double inHiY = Math.max(inHiFromVdd, inHiFromMos);
TrackRouter inHi = new TrackRouterH(tech.m1(), 3, inHiY, tech, inv);
inHi.connect(inv.findExport("in"));
for (int i=0; i<pmos.nbGates(); i++) {
inHi.connect(pmos.getGate(i, 'T'));
}
}
// connect up output
TrackRouter outHi = new TrackRouterH(tech.m2(), 4, outHiY, tech, inv);
outHi.connect(inv.findExport("out"));
for (int i=1; i<pmos.nbSrcDrns(); i += 2) {
outHi.connect(pmos.getSrcDrn(i));
}
TrackRouter outLo = new TrackRouterH(tech.m2(), 4, outLoY, tech, inv);
outLo.connect(inv.findExport("out"));
for (int i = 1; i < nmos.nbSrcDrns(); i += 2) {
outLo.connect(nmos.getSrcDrn(i));
}
// add wells
double wellMinX = 0;
double wellMaxX = outX + 2 + 1.5; // m1_wid/2 + m1m1_space/2
stdCell.addNmosWell(wellMinX, wellMaxX, inv);
stdCell.addPmosWell(wellMinX, wellMaxX, inv);
// add essential bounds
stdCell.addEssentialBounds(wellMinX, wellMaxX, inv);
// perform Network Consistency Check
stdCell.doNCC(inv, "inv{sch}");
return inv;
}
}