Question
Download Solution PDFThe contents of register (B) and accumulator (A) of an 8085 microprocessor are 3C H and 89 H respectively. The contents of A and the status of carry flag (CY) and sign flag (S) after executing SUB B instructions are
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFGiven that,
Contents of register B = 3C H.
Contents of accumulator A = 89 H.
The subtraction A-B results in 89H - 3CH, which is equal to 4D H. The carry flag (CY) is set since there is no borrow. The sign flag (S) is set because the result is positive.
It indicates that the accumulator A will have the value 4D H, the carry flag (CY) will be 1, and the sign flag (S) will be S -1, which is effectively 1.
Here, option 2 is correct.
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