/* Copyright (c) 2010, Carl Burch. License information is located in the
* com.cburch.logisim.Main source code and at www.cburch.com/logisim/. */
package com.cburch.logisim.std.arith;
import java.awt.Color;
import java.awt.Graphics;
import com.cburch.logisim.data.Attribute;
import com.cburch.logisim.data.BitWidth;
import com.cburch.logisim.data.Bounds;
import com.cburch.logisim.data.Direction;
import com.cburch.logisim.data.Location;
import com.cburch.logisim.data.Value;
import com.cburch.logisim.instance.InstanceFactory;
import com.cburch.logisim.instance.InstancePainter;
import com.cburch.logisim.instance.InstanceState;
import com.cburch.logisim.instance.Port;
import com.cburch.logisim.instance.StdAttr;
import com.cburch.logisim.tools.key.BitWidthConfigurator;
import com.cburch.logisim.util.GraphicsUtil;
public class Multiplier extends InstanceFactory {
static final int PER_DELAY = 1;
private static final int IN0 = 0;
private static final int IN1 = 1;
private static final int OUT = 2;
private static final int C_IN = 3;
private static final int C_OUT = 4;
public Multiplier() {
super("Multiplier", Strings.getter("multiplierComponent"));
setAttributes(new Attribute[] { StdAttr.WIDTH },
new Object[] { BitWidth.create(8) });
setKeyConfigurator(new BitWidthConfigurator(StdAttr.WIDTH));
setOffsetBounds(Bounds.create(-40, -20, 40, 40));
setIconName("multiplier.gif");
Port[] ps = new Port[5];
ps[IN0] = new Port(-40, -10, Port.INPUT, StdAttr.WIDTH);
ps[IN1] = new Port(-40, 10, Port.INPUT, StdAttr.WIDTH);
ps[OUT] = new Port( 0, 0, Port.OUTPUT, StdAttr.WIDTH);
ps[C_IN] = new Port(-20, -20, Port.INPUT, StdAttr.WIDTH);
ps[C_OUT] = new Port(-20, 20, Port.OUTPUT, StdAttr.WIDTH);
ps[IN0].setToolTip(Strings.getter("multiplierInputTip"));
ps[IN1].setToolTip(Strings.getter("multiplierInputTip"));
ps[OUT].setToolTip(Strings.getter("multiplierOutputTip"));
ps[C_IN].setToolTip(Strings.getter("multiplierCarryInTip"));
ps[C_OUT].setToolTip(Strings.getter("multiplierCarryOutTip"));
setPorts(ps);
}
@Override
public void propagate(InstanceState state) {
// get attributes
BitWidth dataWidth = state.getAttributeValue(StdAttr.WIDTH);
// compute outputs
Value a = state.getPort(IN0);
Value b = state.getPort(IN1);
Value c_in = state.getPort(C_IN);
Value[] outs = Multiplier.computeProduct(dataWidth, a, b, c_in);
// propagate them
int delay = dataWidth.getWidth() * (dataWidth.getWidth() + 2) * PER_DELAY;
state.setPort(OUT, outs[0], delay);
state.setPort(C_OUT, outs[1], delay);
}
@Override
public void paintInstance(InstancePainter painter) {
Graphics g = painter.getGraphics();
painter.drawBounds();
g.setColor(Color.GRAY);
painter.drawPort(IN0);
painter.drawPort(IN1);
painter.drawPort(OUT);
painter.drawPort(C_IN, "c in", Direction.NORTH);
painter.drawPort(C_OUT, "c out", Direction.SOUTH);
Location loc = painter.getLocation();
int x = loc.getX();
int y = loc.getY();
GraphicsUtil.switchToWidth(g, 2);
g.setColor(Color.BLACK);
g.drawLine(x - 15, y - 5, x - 5, y + 5);
g.drawLine(x - 15, y + 5, x - 5, y - 5);
GraphicsUtil.switchToWidth(g, 1);
}
static Value[] computeProduct(BitWidth width, Value a, Value b, Value c_in) {
int w = width.getWidth();
if (c_in == Value.NIL || c_in.isUnknown()) c_in = Value.createKnown(width, 0);
if (a.isFullyDefined() && b.isFullyDefined() && c_in.isFullyDefined()) {
long sum = (long) a.toIntValue() * (long) b.toIntValue()
+ (long) c_in.toIntValue();
return new Value[] { Value.createKnown(width, (int) sum),
Value.createKnown(width, (int) (sum >> w)) };
} else {
Value[] avals = a.getAll();
int aOk = findUnknown(avals);
int aErr = findError(avals);
int ax = getKnown(avals);
Value[] bvals = b.getAll();
int bOk = findUnknown(bvals);
int bErr = findError(bvals);
int bx = getKnown(bvals);
Value[] cvals = c_in.getAll();
int cOk = findUnknown(cvals);
int cErr = findError(cvals);
int cx = getKnown(cvals);
int known = Math.min(Math.min(aOk, bOk), cOk);
int error = Math.min(Math.min(aErr, bErr), cErr);
int ret = ax * bx + cx;
Value[] bits = new Value[w];
for (int i = 0; i < w; i++) {
if (i < known) {
bits[i] = ((ret & (1 << i)) != 0 ? Value.TRUE : Value.FALSE);
} else if (i < error) {
bits[i] = Value.UNKNOWN;
} else {
bits[i] = Value.ERROR;
}
}
return new Value[] { Value.create(bits),
error < w ? Value.createError(width) : Value.createUnknown(width) };
}
}
private static int findUnknown(Value[] vals) {
for (int i = 0; i < vals.length; i++) {
if (!vals[i].isFullyDefined()) return i;
}
return vals.length;
}
private static int findError(Value[] vals) {
for (int i = 0; i < vals.length; i++) {
if (vals[i].isErrorValue()) return i;
}
return vals.length;
}
private static int getKnown(Value[] vals) {
int ret = 0;
for (int i = 0; i < vals.length; i++) {
int val = vals[i].toIntValue();
if (val < 0) return ret;
ret |= val << i;
}
return ret;
}
}