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#!/usr/bin/python
from components.ram import Ram
class Caretaker:
def __init__(self,ramSize):
self.objects=dict() # Create empty objects pool
## Add registers to pool ##
for reg in ["MAR","MDR", "PC", "MBR", "SP","LV","CPP","TOS","OPC","H"]:
self.objects[reg]=0
self.objects["RAM"]=Ram(self,ramSize) # Create ram
def __getitem__(self,key):
if key=="MBRU": # If we ask for unsigned
return(abs(self.objects["MBR"]))
elif key== "MBR": # If we ask for signed
if self.objects[key] < 0: # If its already signed
return(self.objects[key])
elif self.objects[key]>>7==1: # Otherwise compute its python version
return(-((self.objects[key]-1)^0xFF)) # Reverse 2 complements to get an unsigned number then negate it
else: # Otherwise it is positive
return(self.objects[key])
return(self.objects[key])
def __setitem__(self,key,value):
if key!="RAM":
if ((-(2**7-1))>value or value>(2**8)-1) and (key=="MBR" or key=="MBRU"):
raise RuntimeError("Value {} cannot fit in {} register (-(2^7-1) minimum value and (2^7-1) maximum value)".format(value,key))
elif (-(2**31-1)>value or value>(2**32)-1) and (key!="MBR" and key!="MBRU"):
raise RuntimeError("Value {} cannot fit in {} register (2^32-1 maximum value)".format(value,key))
self.objects[key]=value
def items(self):
return(self.objects.items())
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