What does CMP does in 8085?

What does CMP does in 8085?

Compare (register or memory) with accumulator (CMP R/M) – 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 use of CMP instruction?

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.

What is CMP B?

The jne description: Jump to Label if Zero-bit is reset. 455a: f290 8500 1024 cmp.b #0x85, &0x2410 4560: 0720 jne #0x4570 So the cmp. b is comparing the byte (as indicated by the .

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.

Is Sub preferred over CMP instruction?

The main difference between cmp and sub is that cmp does not store the result of the subtract operation; it performs subtraction only to set the status flags. Similarly, two registers can be compared to see if they both have the same value.

Which flag are affected by CMP instruction?

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 the meaning of the instruction CMP A?

CoMPareAccumulator

What are the different types of operators?

Let us discuss in detail the function of each type of operator.

• Arithmetic Operators.
• Relational Operators.
• Logical Operators.
• Assignment Operators.
• Bitwise Operators.
• Miscellaneous Operators.

What is operands in C?

(c) (d) Operator and operand examples. + and * are arithmetic operators while the symbols appearing on either side of them are operands. Constants, variables, and function return values may all serve as operands and may be intermixed when forming expressions.

What is effective address?

The effective address is the location of an operand of the instruction, since the operand is the data to be accessed. Immediate instructions use their operand to hold the data needed to complete the instruction.

How effective address is calculated?

Effective address or Offset: An offset is determined by adding any combination of three address elements: displacement, base and index. Displacement: It is an 8 bit or 16 bit immediate value given in the instruction. Base: Contents of base register, BX or BP. Index: Content of index register SI or DI.