ADDRESS MATCHING CIRCUIT IN BREAKPOINT GENERATION UNIT

摘要

PURPOSE: An address matching circuit in a breakpoint generation unit is provided to generate a breakpoint of a computer program in case that a constraint between a breakpoint address and a range reduced by using smaller hardware resources does not exist. CONSTITUTION: A subtracter(200) receives and subtracts a breakpoint address and a memory reference address. The first detector(210) detects whether the rest bits except low-level 2 bits are entirely '0' in case that a subtraction result is a positive number. The second detector(230) detects whether the rest bits except low-level 2 bits are entirely 1 in case that a subtraction result is a negative number. The second comparator(240) compares whether the low-level 2 bits is larger than an inverse OS . The first AND gate(250) logically multiplies signals outputted from the first detector(210) and the first comparator(220). The second AND gate logically multiplies signals outputted from the second detector(230) and the second comparator(240). An AND gate(270) logically adds signals outputted from the first and the second AND gate(250,260), and generates the final matching signal.