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Everything except error checking
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@quazi-irfan
quazi-irfan committed Nov 15, 2016
1 parent ca8f746 commit 6d7fd52
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Showing 2 changed files with 74 additions and 39 deletions.
7 changes: 5 additions & 2 deletions src/Assembler/Main.java
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Original file line number Diff line number Diff line change
Expand Up @@ -27,9 +27,12 @@ public static void main(String[] args) throws IOException{
SymbolTable symbolTable = new SymbolTable();
LinkedList<Literal> literalTable = new LinkedList<>();

String inputFile = "CS_Prog.txt";
String inputFile = "SICXE Program 4.txt";
// String inputFile = "CS_Prog.txt";
// String inputFile = "A3_3.txt";
System.out.println("Reading from : " + inputFile );

System.out.println("> Generated Intermediate File");
System.out.println("\n> Generated Intermediate File");
Pass1Utility.populateTableGenerateInt(inputFile, symbolTable, literalTable);

System.out.println("\n> Symbol Value\trflag\tiflag\tmflag");
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106 changes: 69 additions & 37 deletions src/Assembler/Pass2Utility.java
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Original file line number Diff line number Diff line change
Expand Up @@ -18,6 +18,8 @@
*/
public class Pass2Utility {
public static ArrayList<String> MRecordLists = new ArrayList<>();
public static boolean useBase = false;
public static int baseAddress = 0;

public static void generateObj(String inputFile, SymbolTable symbolTable, LinkedList<Literal> literalTable) throws IOException{
inputFile = inputFile.substring(0, inputFile.indexOf('.')).concat(".int");
Expand All @@ -41,7 +43,13 @@ public static void generateObj(String inputFile, SymbolTable symbolTable, Linked
continue;
}

if(fields[2].equals("BASE") | fields[2].equals("EQU") | fields[2].equals("RESB") | fields[2].equals("RESW")){
if(fields[2].equals("BASE")){
OperandUtility.evaluateOperand(symbolTable, literalTable, fields[3]);
baseAddress = OperandUtility.operand.value;
useBase = true;
}

if(fields[2].equals("EQU") | fields[2].equals("RESB") | fields[2].equals("RESW")){
System.out.println(instruction + " -"); // printing objectcode
instruction = reader.readLine();
continue;
Expand Down Expand Up @@ -102,7 +110,6 @@ public static void generateObj(String inputFile, SymbolTable symbolTable, Linked
objectCode = fields[3];

System.out.println(instruction + " " + objectCode.toUpperCase()); // printing objectcode
MRecordLists.addAll(generateMRecord(fields, symbolTable));
instruction = reader.readLine();
continue;
}
Expand Down Expand Up @@ -177,12 +184,15 @@ else if(fields[2].equals("WORD")){
System.out.println(instruction + " " + objectCode);
instruction = reader.readLine();
continue;
} else {
OperandUtility.evaluateOperand(symbolTable, literalTable, fields[3]);
}

// if there is #1000 or #ARRAY as operand in format 3 instruction
// for non-relocatable operand, appended the value at the end of object code
if(!OperandUtility.operand.relocability & fields[3].charAt(0) != '='){ // if rflag = false == true AND there is no literal
objectCode = objectCode.concat(Utility.pad(OperandUtility.operand.value, 4)); // #ARRAY OR 5 or 5+7
XBPE += 2;
objectCode = objectCode.concat(Utility.pad(XBPE, 1)).concat(Utility.pad(OperandUtility.operand.value, 3)); // #ARRAY OR 5 OR 5+7

System.out.println(instruction + " " + objectCode); // printing objectcode
}
Expand All @@ -192,30 +202,52 @@ else if(fields[2].equals("WORD")){
else {
int targetAddress;
if(!(fields[3].charAt(0) == '='))
targetAddress = OperandUtility.operand.value - getNextLineCounter(Integer.parseInt(fields[0], 16), fields[2],fields[3]);
targetAddress = OperandUtility.operand.value - getNextLineCounter(fields);
else
targetAddress = findLiteralAddress(literalTable, fields[3]) - getNextLineCounter(Integer.parseInt(fields[0], 16), fields[2],fields[3]);

// Use P bit
// supported positive range 0 to + 2047 | 000 to 7FF | 0000 0000 0000 to 0111 1111 1111
// supported negative rnage -2048 to -1 | 800 to FFF | 0111 1111 1111 to 1111 1111 1111
if (targetAddress >= -2048 && targetAddress <= 2047) {
XBPE += 2;
objectCode = objectCode.concat(Utility.pad(XBPE, 1)).concat(Utility.pad(targetAddress, 3));

System.out.println(instruction + " " + objectCode); // printing objectcode
targetAddress = findLiteralAddress(literalTable, fields[3]) - getNextLineCounter(fields);

// When we need to move forward
if(OperandUtility.operand.value >= Integer.parseInt(fields[0], 16)){
// check P range
if (targetAddress >= 0 && targetAddress <= 2047) {
XBPE += 2;
objectCode = objectCode.concat(Utility.pad(XBPE, 1)).concat(Utility.pad(targetAddress, 3));
System.out.println(instruction + " " + objectCode + " (Pos address within P range)"); // printing objectcode
instruction = reader.readLine();
continue;
}

// check for B range
else {
// use Base register
if(useBase){
XBPE += 4;
targetAddress = OperandUtility.operand.value - baseAddress;
if(targetAddress >= 0 && targetAddress <= 4095) { // 2^12 - 1 = 4096 - 1 = 4095
objectCode = objectCode.concat(Utility.pad(XBPE, 1)).concat(Utility.pad(targetAddress, 3));
System.out.println(instruction + " " + objectCode + " (Using Base Relative addressing)"); // printing objectcode
} else {
System.out.println(instruction + " Error : Address out of range " + Utility.pad(targetAddress, 5));
}
}
// Use of Base register isn't set
else {
System.out.println(instruction + " Error : Needs Base addressing to reach " + Utility.pad(targetAddress, 5)); // printing objectcode
}
}
}

// Use B bit, supported range 0 to 4095
else {
// load the B register LDB #ARRAY
// and use the BASE directive BASE ARRAY
// before using Base relative addressing

XBPE += 3;
// TODO handle base register addressing mode
System.out.println("USE BASE RELATIVE ADDRESSING!");
// When we need to move backward
else if(OperandUtility.operand.value < Integer.parseInt(fields[0], 16)){
if(targetAddress <= -1 && targetAddress >= -2048){
XBPE += 2;
objectCode = objectCode.concat(Utility.pad(XBPE, 1)).concat(Utility.pad(targetAddress, 3));
System.out.println(instruction + " " + objectCode + " (Neg address within P range)"); // printing objectcode
} else {
System.out.println(instruction + " Error : Addressing can't be reached via B or P."); // printing objectcode
}
}

}
}

Expand Down Expand Up @@ -356,6 +388,7 @@ else if(operand.Nbit && !operand.Ibit)
* @return
*/
private static int findLiteralAddress(LinkedList<Literal> literalTable, String literalExpression){
// remove the '=' character since none of the literal on literal table has that character
literalExpression = literalExpression.substring(1);

for(Literal literal : literalTable){
Expand All @@ -368,35 +401,34 @@ private static int findLiteralAddress(LinkedList<Literal> literalTable, String l

/**
*
* @param currentLineCounter
* @param opcode
* @param operand
* @param fields
* @return
*/
private static int getNextLineCounter(int currentLineCounter, String opcode, String operand){
int opcodeFormat = OpcodeUtility.getFormat(opcode);
private static int getNextLineCounter(String[] fields){
int currentLineCounter = Integer.parseInt(fields[0], 16);
int format = OpcodeUtility.getFormat(fields[2]);

// handle LDA STA
if(opcodeFormat != 0){
return currentLineCounter + opcodeFormat;
if(format != 0){
return currentLineCounter + format;
}

// handle BYTE, WORD, RESB, RESW
else {
if(opcode.equals("BYTE")){
String temp = operand.substring(operand.indexOf('\'')+1, operand.lastIndexOf('\''));
if(operand.contains("C"))
if(fields[2].equals("BYTE")){
String temp = fields[3].substring(fields[3].indexOf('\'')+1, fields[3].lastIndexOf('\''));
if(fields[2].contains("C"))
return currentLineCounter + temp.length();
else
return currentLineCounter + temp.length() / 2;
}

else if(opcode.equals("RESW")){
return currentLineCounter + 3 * Integer.parseInt(operand);
else if(fields[2].equals("RESW")){
return currentLineCounter + 3 * Integer.parseInt(fields[3]);
}

else if(opcode.equals("RESB")){
return currentLineCounter + Integer.parseInt(operand);
else if(fields[2].equals("RESB")){
return currentLineCounter + Integer.parseInt(fields[3]);
}
}

Expand Down

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