Contents
How do you set a zero flag?
Along with a carry flag, a sign flag and an overflow flag, the zero flag is used to check the result of an arithmetic operation, including bitwise logical instructions. It is set to 1, or true, if an arithmetic result is zero, and reset otherwise.
How do you know if zero flag is set?
When used with TEST, the zero flag will be set if the bit being tested is zero. The zero flag is also used in the JA (jump if above), JB (jump if below) and similar conditional jump instructions. Set if the most significant bit (the leftmost bit) of the result is 1.
What is the working of O flag?
Status Flags
| Flag Bit | Function |
|---|---|
| CY | This is carry bit. If some operations are generating carry after the operation this flag is set to 1 |
| O | The overflow flag is set to 1 when the result of a signed operation is too large to fit. |
What is the importance of the zero flag?
The purpose of the zero flag is to indicate whether the execution of the last instruction that affected the zero flag has produced a zero result. If the result was zero, ZF = 1; otherwise, ZF = O.
Which instruction does not affect carry flag?
NOT instruction does not affect any flags! NEG instruction affects these flags only: CF, ZF, SF, OF, PF, AF. NOT – Reverse each bit of operand.
When do you set the zero flag to 0?
Zero Flag (Z) – After any arithmetical or logical operation if the result is 0 (00)H, the zero flag becomes set i.e. 1, otherwise it becomes reset i.e. 0. 00H zero flag is 1. from 01H to FFH zero flag is 0 1- zero result
When to use carry flag or zero flag?
the zero flag is quite simple if the result of the operation is a zero the zero flag will be set otherwise it will be clear. The carry flag is used a number of ways but in this case with an add operation, it is the carry out bit, an unsigned overflow.
What does the zero flag mean in 6510?
The zero flag indicates the result of a 6510 instruction as being numerically zero (0) or non-zero. If an operation results in a value of zero, then the flag is set (1). If an operation results in a non-zero value, then the flag is cleared (0).
How to reset the sign flag to 0?
These set of instructions will reset the sign flag to 0 as 40 – 30 is a positive number. Zero Flag (Z) – After any arithmetical or logical operation if the result is 0 (00)H, the zero flag becomes set i.e. 1, otherwise it becomes reset i.e. 0. 00H zero flag is 1.