PIC16单片机汇编语言“indir equ 0和timer equ 1和 pc equ 2代表什么意思

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
public class Counter1 extends Applet {
private int count = 0;
private Button
onOff = new Button("on_of"),
start = new Button("Start");
private TextField t = new TextField(10);
private boolean runFlag = true;
public void init() {
add(t);
start.addActionListener(new StartL());
add(start);
onOff.addActionListener(new OnOffL());
add(onOff);
}
public void go(){new Thread(){
public void run(){
try {
Thread.currentThread().sleep(1000);
} catch (InterruptedException e){}

if(runFlag)
t.setText(Integer.toString(count++));
}

}.start();

}

class StartL implements ActionListener {
public void actionPerformed(ActionEvent e) {
go();
}
}
class OnOffL implements ActionListener {
public void actionP