Neha(DSPT5)

ls8/cpu.py

@@ -2,40 +2,76 @@
 
 import sys
 
+HLT = 0b00000001
+LDI = 0b10000010
+PRN = 0b01000111
+MUL = 0b10100010
+PUSH = 0b1000101
+POP = 0b1000110
+CALL = 0b01010000
+RET = 0b00010001
+ADD  = 0b10100000
+SP = 7
+
 class CPU:
     """Main CPU class."""
 
     def __init__(self):
         """Construct a new CPU."""
-        pass
+        self.ram = [0] *256
+        self.pc = 0 #point to the instruction in memory
+        self.reg = [0] *8
+        self.reg[7] = 0xF4
+        self.running = False
 
-    def load(self):
+    def load(self, filename):
         """Load a program into memory."""
-
         address = 0
-
+        with open(filename) as f:
+            for line in f:
+                comment_split = line.split('#')
+                num = comment_split[0].strip()
+                if num =='':
+                    continue
+                command = int(num, 2)
+                self.ram_write(command, address)
+                address +=1
+
+
+
+
+
         # For now, we've just hardcoded a program:
 
         program = [
             # From print8.ls8
-            0b10000010, # LDI R0,8
+            0b10000010,# LDI R0,8
             0b00000000,
             0b00001000,
+            0b10000010,# LDI R1,9
+            0b00000001,
+            0b00001001,
+            0b10100010, # MUL R0,R1
+            0b00000000,
+            0b00000001,
             0b01000111, # PRN R0
             0b00000000,
             0b00000001, # HLT
         ]
 
-        for instruction in program:
-            self.ram[address] = instruction
-            address += 1
-
+        # for instruction in program:
+        #     self.ram[address] = instruction
+        #     address += 1
+        
 
     def alu(self, op, reg_a, reg_b):
         """ALU operations."""
 
         if op == "ADD":
             self.reg[reg_a] += self.reg[reg_b]
+        elif op == "MUL":
+            self.reg[reg_a] *=self.reg[reg_b]
+
         #elif op == "SUB": etc
         else:
             raise Exception("Unsupported ALU operation")
@@ -59,7 +95,72 @@ def trace(self):
             print(" %02X" % self.reg[i], end='')
 
         print()
+    def ram_read(self, address):
+        '''MAR contain address that is being read or written too'''
+        return self.ram[address]
+    def ram_write(self, value, address):
+        '''MDR contains the data to read or write '''
+        self.ram[address] = value
+        #self.running = True
 
     def run(self):
         """Run the CPU."""
-        pass
+        #self.load()
+        #running = True
+        while not self.running:
+           commondToExecute = self.ram[self.pc]
+           opr_a = self.ram[self.pc + 1]
+           opr_b = self.ram[self.pc + 2]
+           if commondToExecute == HLT:
+               self.running = True
+               self.pc +=1
+           elif commondToExecute == LDI:
+               self.reg[opr_a] = opr_b
+               self.pc +=3
+           elif commondToExecute ==PRN:
+               print(self.reg[opr_a])
+               self.pc +=2
+           elif commondToExecute == MUL:
+               self.alu('MUL', opr_a, opr_b)
+               self.pc +=3
+           elif commondToExecute == ADD:
+               self.alu('ADD', opr_a, opr_b)
+               self.pc +=3
+           elif commondToExecute == PUSH:
+               #decrement stack pointer
+               self.reg[SP] -=1
+               #write the value stored in register onto stack
+               ValueToStore = self.reg[opr_a]
+               self.ram_write(ValueToStore, self.reg[SP])
+               self.pc +=2
+           elif commondToExecute == POP:
+                #save the value on the top of stack onto the register
+                topmostValue = self.ram_read(self.reg[SP])
+                self.reg[opr_a]=topmostValue
+                # increment the stack pointer
+                self.reg[SP] +=1
+                self.pc +=2
+           elif commondToExecute == CALL:
+                #store address of the next instruction onto the stack
+                self.reg[SP] -=1
+                addressOfNextInstruction = self.pc+2
+                self.ram_write(addressOfNextInstruction, self.reg[SP])
+                #jump to the address of the given register
+                regToGetAdressFrom = opr_a
+                AddressToJumpTo = self.reg[opr_a]
+                self.pc = AddressToJumpTo
+           elif commondToExecute == RET:
+                #pop the top most value from the stack
+                AdressToReturnTo = self.ram_read(self.reg[SP])
+                #set the pc to the same value
+                self.pc = AdressToReturnTo
+                self.reg[SP] +=1
+           else:
+              print("IDK this instruction Existing")
+              sys.exit(1)
+
+
+
+
+
+

ls8/ls8.py

@@ -5,7 +5,14 @@
 import sys
 from cpu import *
 
-cpu = CPU()
+if len(sys.argv) != 2:
+    print(argv_err_msg)
+    sys.exit(1)
+else:
+    # cd ../S7-Computer-Architecture/M1-4/Computer-Architecture/ls8
+    # python3 ls8.py examples/print8.ls8
+    file_name = sys.argv[1]
 
-cpu.load()
+cpu = CPU()
+cpu.load(file_name)
 cpu.run()