Assembly Language - Mnemonic and Opcode

Assembly Language - Mnemonic and Opcode

            So in the previous post we have seen how addressing modes works and why they are important although that was just an introductory part (Don't worry I'll go into much deeper when time comes)... Now in this post I am going to talk about the mnemonic and opcode... 

            If you are a computer science student then you have already heard this term OPCODE in the microprocessor or advance microprocessor lecture and also you heard like opcode means operational code and it tells microprocessor that which operation to perform and yeah that's somewhat correct right ........ But don't worry because I am going to clear the doubt about these two terms... So I am first going to explain the mnemonics and then move on to the opcode...

Mnemonic :-

• Mnemonic means human readable format of an assembly instruction without operands.

Opcode :-

• Opcode means operational code and it tells microprocessor that which operation to perform.

• An Operational Code is a 1 byte or 2 byte (sometimes 3 byte) means it is generally range from 0x00 to 0xff.

Confused.... Let's understand this with some examples...

Examples :-

• Both are same things mnemonic and opcode with little different you can see in the diagram below

• Like PUSH instruction has the opcode 0x68....

• Then the mnemonic for the opcode 0x68 would be PUSH...

You can find the opcode table :-    Click Here

Now that's it for this post see you guys in the next one byeeeee..... :)