GENERAL DESCRIPTION
The Z8400/Z84C00 CPUs are fourth-generation enhanced microprocessors with exceptional computational power. They offer higher system throughput and more efficient memory utilization than comparable second- and thirdgeneration microprocessors. The speed offerings from 6 - 20 MHz suit a wide range of applications which migrate software. The internal registers contain 208 bits of read/ write memory that are accessible to the programmer. These registers include two sets of six general purpose registers which may be used individually as either 8-bit registers or as 16-bit register pairs. In addition, there are two sets of accumulator and flag registers. A group of “Exchange” instructions makes either set of main or alternate registers accessible to the programmer. The alternate set allows operation in foreground-background mode or it may be reserved for very fast interrupt response.

FEATURES
■ The Extensive Instruction Set.Contains 158 Instructions, Including the 8080A Instructions Set as a Subset.
■ Single 5 Volt Power Supply
■ NMOS Version for Low Cost, High Performance Solutions; CMOS Version for High Performance, Low Power Designs.
■ NMOS Z084004 - 4 MHz Z0840006 - 6.17 MHz Z084008 - 8 MHz
■ CMOS Z0840006 - DC to 6.17 MHz Z84C0008 - DC to 8 MHz Z84C0010 - DC to 10 MHz Z84C0020 - DC to 20 MHz
■ 6 MHz Version can be Operated at 6.144 MHz Clock Speed
■ The Z80 Microprocessors and Associated Family of Peripherals can be Linked by a Vectored Interrupt System. This System can be Daisy-Chained to Allow Implementation of a Priority Interrupt Scheme.
■ Duplicate Set of Both General-Purpose and Flag Registers
■ Two 16-Bit Index Registers
■ Three Modes of Maskable Interrupts:
    - Mode 0 - 8080A Similar
    - Mode 1 - Non-Z80 Environment, Location 38H
    - Mode 2 - Z80 Family Peripherals, Vectored Interrupts
■ On-Chip Dynamic Memory Refresh Counter