What is CMP in 8086 microprocessor?

What is CMP in 8086 microprocessor?

The CMP instruction compares two operands. It is generally used in conditional execution. This instruction basically subtracts one operand from the other for comparing whether the operands are equal or not. It is used along with the conditional jump instruction for decision making.

Which flags are affected by CMP instruction in 8086?

CMP and TEST instructions affect flags only and do not store a result (these instruction are used to make decisions during program execution). These instructions affect these flags only: CF, ZF, SF, OF, PF, AF.

What is CMP in microprocessor?

Microprocessor8085. In 8085 Instruction set, CMP is a mnemonic that stands for “CoMPareAccumulator” and hereR stands for any of the following registers, or memory location M pointed by HL pair. R = A, B, C, D, E, H, L, or M. This instruction is used to compare contents of the Accumulator with given register R.

How many flags are affected after executing CMP instruction?

only carry and zero flags will be affected. no flags will be affected. While CMP B instruction executes, microprocessor compares the contents of register B with the contents of the accumulator.

What is the difference between CMP and sub instruction?

What is the difference between CMP and sub instruction? CMP is used for comparing 2 registers by subtraction them from one another, but answer is not saved, whereas SUB subtracts 2 registers and saves the answer.

What is the difference between macro and procedure and state their syntax?

A macro is used for a small number of instructions; mostly, less than ten instructions, while a procedure is used for a large number of instructions; mostly, higher than ten instructions. Hence, this is the main difference between macro and procedure.

What does CMP do?

A comprehensive metabolic panel (CMP) is a test that measures 14 different substances in your blood. It provides important information about your body’s chemical balance and metabolism. Metabolism is the process of how the body uses food and energy.

How does CMP work in 8085?

The 8085 instruction set has two types of Compare operations: Compare with accumulator (CMP) and Compare immediate with accumulator (CPI). This is a 1-byte instruction. It compares the data byte in the register or memory with the contents of accumulator. If A less than (R/M), the CY flag is set and Zero flag is reset.

What is the similarity and difference between subtract and compare instruction?

The compare and subtract instructions in the 8085 both subtract one operand from another, and set flags accordingly. The subtract instruction stores the result in the accumulator, while the compare instruction does not – except for the flags, the compare instruction “throws” the result away.

What kind of instructions does an 8086 microprocessor do?

The 8086 microprocessor supports 8 types of instructions − Data Transfer Instructions; Arithmetic Instructions; Bit Manipulation Instructions; String Instructions; Program Execution Transfer Instructions (Branch & Loop Instructions) Processor Control Instructions; Iteration Control Instructions; Interrupt Instructions

What are the characteristics of the CMP instruction?

Mention the characteristics of the CMP instructions. – The CMP instruction can be used to compare two 8-bit or two 16-bit numbers. – Whenever a compare operation is performed the result of such an operation reflects in one of the six status flags CF, AF, OF, PF, SF and ZF.

How are ins and outs used in a microprocessor?

INS/INSB/INSW − Used as an input string/byte/word from the I/O port to the provided memory location. OUTS/OUTSB/OUTSW − Used as an output string/byte/word from the provided memory location to the I/O port. SCAS/SCASB/SCASW − Used to scan a string and compare its byte with a byte in AL or string word with a word in AX.

When to use carry flag C in CMP?

The carry flag C is set after a cmp operation if subtracting src from dest requires a borrow. This occurs only when dest is less than src where dest and src are both unsigned values. For signed operands, the C flag has no meaning.