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What is bit in flag register?
The FLAGS register is the status register that contains the current state of the CPU. The size and meanings of the flag bits are architecture dependent. The adjust flag used to be called auxiliary carry bit in 8080 and half-carry bit in the Zilog Z80 architecture. In i386 architecture the register is 16 bits wide.
How many bits does the flag register as flag status?
16-bit
The flag bits are changed to 0 or 1 depending upon the value of result after arithmetic or logical operations. 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 |
Which register has condition flags?
The status register lets an instruction take action contingent on the outcome of a previous instruction. Typically, flags in the status register are modified as effects of arithmetic and bit manipulation operations. For example, a Z bit may be set if the result of the operation is zero and cleared if it is nonzero.
Why is a flag register necessary?
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 are the 5 flags of the Intel 8080?
There are five types of flags associated with the implementation of instructions on the microprocessor 8080. They are sign, zero, parity, carry and auxiliary carry, and these flags are represented by a 1-bit register in the CPU. A flag is set by forcing the bit to 1, and reset by forcing the bit to 0.
How many flags are there in an 8-bit register?
Flag is an 8-bit register having five 1-bit flags. There are five types of flags associated with the implementation of instructions on the microprocessor 8080. They are sign, zero, parity, carry and auxiliary carry, and these flags are represented by a 1-bit register in the CPU.
What’s the difference between Intel 8080 and 8085?
There is some difference in the handling of the auxiliary carry flag by the logical AND instructions in the 8080 processor and the 8085 processor. The 8085 logical AND instructions always set the auxiliary flag ON. The 8080 logical AND instructions set the flag to reflect the logical OR of bit 3 of the values involved in the AND operation.
How big is the FLAGS register in Intel?
From Wikipedia, the free encyclopedia The FLAGS register is the status register in Intel x86 microprocessors that contains the current state of the processor. This register is 16 bits wide. Its successors, the EFLAGS and RFLAGS registers, are 32 bits and 64 bits wide, respectively.