What is Flag Register and its types?
The FLAGS register is the status register that contains the current state of a CPU. The carry, parity, adjust, zero and sign flags are included in many architectures. The adjust flag used to be called auxiliary carry bit in 8080 and half-carry bit in the Zilog Z80 architecture.
What are the components of flag register?
Flags register in 8085 Microprocessor
- Carry flag (Cy),
- Auxiliary carry flag (AC),
- Sign flag (S),
- Parity flag (P), and.
- Zero flag (Z).
What are flags in computer architecture?
A flag is one or more data bits used to store binary values as specific program structure indicators. A computer interprets a flag value in relative terms or based on the data structure presented during processing, and uses the flag to mark a specific data structure.
What is the role of flag register?
The Flag register is a Special Purpose Register. Depending upon the value of result after any arithmetic and logical operation the flag bits become set (1) or reset (0). If the MSB is 0, it indicates the number is positive and the sign flag becomes reset i.e. 0.
What is Flag register with example?
The flag register is one of the special purpose register. The flag bits are changed to 0 or 1 depending upon the value of result after arithmetic or logical operations….Status Flags.
| Flag Bit | Function |
|---|---|
| O | The overflow flag is set to 1 when the result of a signed operation is too large to fit. |
How many flag registers are there?
6 flag registers
(a) Status Flags – There are 6 flag registers in 8086 microprocessor which become set(1) or reset(0) depending upon condition after either 8-bit or 16-bit operation.
How many types of flag registers are there?
8086 has 16-bit flag register, and there are 9 valid flag bits….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 are the commonly used condition code flags?
Four commonly used flags are: 1) N (negative) set to 1 if the result is negative, otherwise cleared to 0. 2) Z (zero) set to 1 if the result is 0; otherwise, cleared to 0. 3) V (overflow) set to 1 if arithmetic overflow occurs; otherwise, cleared to 0.
What is a computer flag?
In computer science, a flag is a value that acts as a signal for a function or process. The value of the flag is used to determine the next step of a program. A raised flag says to a program, “Stop – do something different.” A common example of a flag in computer programming is a variable in a while loop.
What is the function of flag?
Flags originally were used mainly in warfare, and to some extent they have remained insignia of leadership, serving for the identification of friend or foe and as rallying points. They are now also extensively employed for signaling, for decoration, and for display.
What are general purpose registers?
General purpose registers are used to store temporary data within the microprocessor. It is of 16 bits and is divided into two 8-bit registers BH and BL to also perform 8-bit instructions. It is used to store the value of the offset.