Special features of Z-80


In this section we will see some advanced features of Zilog Z-80 Microprocessor. These features are basically compared to the Intel 8085 Microprocessor.

The features are listed below −

Sr.No.Features & Description
1Opcode Count
In this Microprocessor there are 698 Opcodes of different lengths.
2Instruction Length
The instructions can be divided into four categories according to their lengths.
There are 202 of 1-byte instructions,
344 of 2-byte instruction
74 of 3-byte instruction
78 of 4-byte instruction
3Opcode Length
The instructions can also be divided into two parts according to the opcode length. In the instruction set, there are instructions with 1-byte opcode and 2-byte opcode.
The number of 1-byte opcode instruction is 252, and number of 2-byte opcode instruction is 446
4New addressing modes, compared to 8085
Like 8085, it has different addressing modes, but here some additional addressing modes are also available. These addressing modes are,
Indexed Addressing Mode
Relative Addressing Mode
Bit Addressing Mode
5New Instructions, compared to 8085
In 698 instructions, there are many instructions, which are different from the 8085. The instruction types are like these,
Block Move
Block Search
Different I/O instructions
Different Exchange Instructions
Decimal adjustment instructions after Addition and Subtraction
Looping instructions
Different Shift and Rotate Instruction
Direct Memory Access type instruction
6Interrupt Structure
In Z-80 there are powerful interrupt structure compared to 8085 Microprocessor.
Updated on 30-Jul-2019 22:30:24