Final answer:
The Flags Register in an 8-bit processor like the Intel 8085 consists of bits representing different conditions such as Sign (S), Zero (Z), Auxiliary Carry (AC), Parity (P), and Carry (C). An 8-bit addition example shows how the flags register changes after an operation.
Step-by-step explanation:
Flags Register and 8-bit Addition Example
The Flags Register is a register within the CPU that is used to indicate the status of the processor and the outcomes of operations. For an 8-bit processor, such as in the Intel 8085 microprocessor, the flags register consists of 8 bits, each representing different flags:
Sign (S): Indicates if the result of an operation is negative
Zero (Z): Indicates if the result of an operation is zero
Auxiliary Carry (AC): Used for BCD (Binary Coded Decimal) arithmetic
Parity (P): Indicates if the number of set bits is even or odd
Carry (C): Indicates if an overflow occurred in the most significant bit
Now let's look at an 8-bit addition example:
Example: Adding 00101101 (45 in decimal) to 00001101 (13 in decimal)
Perform the addition: 00101101 + 00001101 = 00111010 (58 in decimal)
Determine each flag status:
Sign (S) flag remains 0 since the result is not negative.
Zero (Z) flag is 0 because the result is not zero.
Auxiliary Carry (AC) flag could be set if there was a carry from the lower nibble to the upper nibble in BCD arithmetic.
Parity (P) flag is 1 as the result has an even number of set bits.
Carry (C) flag is 0 since there was no overflow or carry out from the most significant bit.
The status of the flags register after this operation might be 00100010, depending on the starting condition and if AC is affected.