ZiLOG Z80 CPU User Manual

About this manual

This manual describes the Z80 8‑bit CPU architecture, its registers, ALU functions, instruction formats, and pin definitions. It includes timing diagrams, interrupt handling procedures, and examples of hardware and software implementation.

The document also contains extensive instruction set tables, assembly language details, status flag descriptions, and guidance for interfacing dynamic memory and peripheral devices.

What's inside

• Architecture
• CPU Registers
• ALU
• Instruction Set
• Pin Description
• Timing Diagrams
• Interrupt Handling
• Hardware and Software Implementation Examples
• Assembly Language
• Status Flags

Specifications

Frequently asked questions

What does the OUTD instruction do?

OUTD transfers a byte from the memory location pointed to by HL to an I/O port selected by register C, then decrements B and HL.

How many T‑states does the OTDR instruction take at 4 MHz?

At 4 MHz, OTDR requires 5.25 T‑states per execution when B ≠ 0, and 4 T‑states when B = 0.