Z84C00 - CMOS Z80 8-Bit CPU Microprocessor | Zilog
MPN: Z84C00 β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.55 | $35.50 |
| 100 | $3.16 | $316.00 |
| 500 | $2.84 | $1,420.00 |
| 1,000 | $2.55 | $2,550.00 |
Z84C00 Overview
A microprocessor (CPU) is the core computation and control block of a computer or embedded system, executing stored instructions and coordinating memory and peripheral I/O. The Z80 family sits within the 8-bit microprocessor hierarchy, which in turn belongs to the broader semiconductor category of embedded processors. First released by Zilog in 1976, the Z80 became one of the most widely deployed CPUs of the early personal computing era.
Key features of the Z84C00 include its extensive 158-instruction set (including 8080A-compatible instructions plus indexed, block, and bit instructions), dual register file with alternate registers for fast context switching, on-chip dynamic RAM refresh counter, and a single 5V supply. The CMOS process delivers significantly lower power consumption than the original NMOS Z8400, making it suitable for battery-powered and industrial systems.
Technically, the Z84C00 is a fourth-generation enhanced microprocessor offering higher system throughput and more efficient memory utilization than second- and third-generation processors, according to the Zilog Z8400/Z84C00 datasheet. It provides 16-bit address bus capability for up to 64 KB of memory addressing, interrupt modes 0, 1, and 2, a non-maskable interrupt (NMI) input, and WAIT states for slow memory.
Typical applications include retro-computing repairs and reproductions (ZX Spectrum, MSX, RC2014 kits), industrial control and instrumentation, embedded controllers, and educational platforms. Its decades-long software ecosystem makes it a natural fit for legacy system maintenance.
Design consideration: verify the speed-grade suffix (06, 08, 10, 20) against your clock source, and note the Z84C00 family was officially discontinued by Zilog with last orders in June 2024, so plan lifecycle sourcing accordingly.
This page synthesizes distributor availability data, drop-in same-family alternatives, and lifecycle guidance not found in the manufacturer datasheet.
Drop-in alternatives for Z84C00 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
Z84C0006PEG
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
Z84C0008PEG
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
Z84C0010PEG
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
Z84C0020PEG
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
Z84C00 Maximum Ratings & Electrical Characteristics
| Core | Z80 |
| Core Size | 8-Bit |
| Number of Cores | 1 Core |
| Speed Grades | 6 MHz, 8 MHz, 10 MHz, 20 MHz |
| Instruction Set | 158 instructions, 8080A compatible |
| Address Bus Width | 16 Bit (64 KB address space) |
| Data Bus Width | 8 Bit |
| Supply Voltage | 5 V |
| Technology | CMOS (NMOS for original Z8400) |
| DRAM Refresh | On-chip refresh counter |
| Interrupt Modes | Mode 0, Mode 1, Mode 2, plus NMI |
| Packages | 40-pin DIP, 44-pin PLCC, 44-pin QFP |
| Mounting Type | Through Hole (DIP) / Surface Mount (PLCC, QFP) |
| Lifecycle Status | End-of-Life (discontinued June 2024) |
Z84C00 Pin Configuration
| Pin 1 | A11 β Address bus bit 11 |
| Pin 2 | A12 β Address bus bit 12 |
| Pin 3 | A13 β Address bus bit 13 |
| Pin 4 | A14 β Address bus bit 14 |
| Pin 5 | A15 β Address bus bit 15 |
| Pin 6 | CLK β System clock input |
| Pin 7 | D4 β Data bus bit 4 |
| Pin 8 | D3 β Data bus bit 3 |
| Pin 9 | D5 β Data bus bit 5 |
| Pin 10 | D6 β Data bus bit 6 |
| Pin 11 | VCC β Power supply (+5 V) |
| Pin 12 | D2 β Data bus bit 2 |
| Pin 13 | D7 β Data bus bit 7 |
| Pin 14 | D0 β Data bus bit 0 |
| Pin 15 | D1 β Data bus bit 1 |
| Pin 16 | INT β Maskable interrupt request (input) |
| Pin 17 | NMI β Non-maskable interrupt request (input) |
| Pin 18 | HALT β Halt state indicator (output) |
| Pin 19 | MREQ β Memory request (output) |
| Pin 20 | IORQ β I/O request (output) |
| Pin 21 | RD β Memory/IO read (output) |
| Pin 22 | WR β Memory/IO write (output) |
| Pin 23 | BUSACK β Bus acknowledge (output) |
| Pin 24 | WAIT β Wait state request (input) |
| Pin 25 | BUSREQ β Bus request for DMA (input) |
| Pin 26 | RESET β Reset (input) |
| Pin 27 | M1 β Machine cycle one / interrupt acknowledge indicator (output) |
| Pin 28 | RFSH β DRAM refresh (output) |
| Pin 29 | GND β Ground |
| Pin 30 | A0 β Address bus bit 0 |
| Pin 31 | A1 β Address bus bit 1 |
| Pin 32 | A2 β Address bus bit 2 |
| Pin 33 | A3 β Address bus bit 3 |
| Pin 34 | A4 β Address bus bit 4 |
| Pin 35 | A5 β Address bus bit 5 |
| Pin 36 | A6 β Address bus bit 6 |
| Pin 37 | A7 β Address bus bit 7 |
| Pin 38 | A8 β Address bus bit 8 |
| Pin 39 | A9 β Address bus bit 9 |
| Pin 40 | A10 β Address bus bit 10 |
Typical Applications
Z84C00 is suitable for 6 applications: Vintage Computer Repair and Reproduction, Industrial Control and Instrumentation, Embedded Educational Platforms, Music and Audio Synthesis Hardware, Arcade Game Board Restoration, New Retro-Style Single Board Computers.
Vintage Computer Repair and Reproduction
The Z84C00 is the definitive repair and reproduction CPU for Z80-based vintage computers including the ZX Spectrum, MSX systems, Amstrad CPC, and RC2014 hobby kits. Because it is pin-to-pin compatible with the original 1976 NMOS Z80 in the 40-pin DIP socket, a faulty CPU can be swapped without any board modification, and the identical 158-instruction set guarantees that tape loading, game ROMs, and CP/M software run exactly as intended. The CMOS process also runs cooler and draws far less current than NMOS originals, reducing stress on aged power supplies. Enthusiasts prize the 20 MHz grade for overclocked builds, as genuine Z84C0020 parts often clock well beyond rating. With the family discontinued in June 2024, sourcing authentic parts from authorized distributors is now critical to avoid remarked fakes.
Recommended
Industrial Control and Instrumentation
Thousands of industrial controllers, test instruments, and process-control boards designed in the 1980s and 1990s were built around the Z80 CPU with Zilog SIO, CTC, and PIO peripherals. The Z84C00 sustains these systems because its interrupt modes 0/1/2, BUSREQ/BUSACK DMA handshake, and cycle timing are identical to the original silicon. Its 16-bit address bus addressing 64 KB of memory matches legacy memory maps exactly, and the on-chip DRAM refresh counter keeps dynamic memory designs working without external refresh logic. In factory-floor environments where a full redesign cannot be justified, dropping a CMOS Z84C00 into the existing socket restores functionality with lower power draw and improved noise margins. Technicians should confirm the 5V rail tolerance and clock grade suffix against the original BOM before replacement.
Recommended
Embedded Educational Platforms
The Z84C00 remains a superb teaching vehicle for computer architecture because its 158-instruction set is small enough to master fully yet rich enough to demonstrate indexed addressing, block transfers, bit manipulation, and vectored interrupt mode 2. University microprocessor labs and self-learners using RC2014-style backplane kits assemble the Z84C00 into through-hole DIP sockets, where the 40-pin package can be replaced cheaply after student experiments go wrong. The single 5V supply, simple external memory interface, and on-chip DRAM refresh mean a minimal working system needs only the CPU, an EPROM/flash, SRAM, and a clock source. Students gain hands-on experience with bus timing, WAIT states for slow memory, and memory-mapped I/O that transfers directly to modern embedded work.
Recommended
Music and Audio Synthesis Hardware
Classic music hardware relied on the Z80: the Roland TR-808's successor generation, numerous MIDI processors, and famous sample-rate converters used Z80 CPUs for sequencing and control. Modern reproductions of these instruments require an authentic Z84C00 because MIDI timing routines are written with cycle-counted delays that assume original Z80 timing; a functionally different CPU would break sync accuracy. The Z84C00's deterministic execution, no pipeline, no cache, makes every instruction duration predictable, which is essential for bit-banged MIDI at 31.25 kbaud and precise gate/trig output timing. Its CMOS construction also lowers electromagnetic emission versus NMOS parts, helping modern reproductions pass EMC testing. Builders of synth clones consistently specify genuine Zilog CMOS parts from authorized stock to preserve timing fidelity.
Recommended
Arcade Game Board Restoration
Golden-age arcade machines from the late 1970s and 1980s commonly used Z80 CPUs clocked at 2.5 to 6 MHz alongside custom sound and video hardware. Restorers replace dead CPUs with the Z84C00 because it drops directly into the original DIP-40 socket and reproduces cycle-exact bus behavior that arcade hardware, video timing chains, and interrupt-driven sound sampling depend on. The CMOS part's lower power consumption reduces heat inside densely packed arcade cabinets, extending the life of neighboring TTL chips. Because arcade boards often run for decades in warm environments, CPU failure is among the most common faults, making reliable socket-compatible replacements the single highest-value repair component. Restorers should verify the crystal frequency and select the matching Z84C00 speed grade, with 6 MHz grade covering most original designs.
Recommended
New Retro-Style Single Board Computers
The RC2014 ecosystem and similar modular retro-computing platforms are new designs that deliberately use classic Z80 silicon. Builders choose the Z84C00 over FPGA soft-cores when they want authentic silicon behavior, including undocumented instruction flags and cycle timing quirks that some Z80 software, copy-protection schemes, and demoscene productions rely on. The through-hole DIP package suits the solderable, socket-based backplane philosophy of these kits, and the 20 MHz CMOS grade lets hobbyists run CP/M Plus comfortably fast while retaining stock-software compatibility at lower clocks. Because Zilog's June 2024 discontinuation has made remaining stock a finite resource, new-kit producers are increasingly qualifying pin-compatible open-silicon Z80 replacements as a second source. Kits typically pair the Z84C00 with Z80 SIO/CTC peripherals for serial and timer functions.
Recommended
Recommended Products Summary
Engineering reference data for Z84C00 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | Z84C0006PEG | Z84C0008PEG | Z84C0010PEG | Z84C0020PEG | Z84C0010VEC00TR |
|---|---|---|---|---|---|---|
| Package | DIP-40 (also PLCC-44/QFP-44 variants) | DIP-40 - same | DIP-40 - same | DIP-40 - same | DIP-40 - same | PLCC-44 - different |
| Brand | Zilog | Zilog | Zilog | Zilog | Zilog | Zilog |
| Max Clock Speed | 6 / 8 / 10 / 20 MHz (per grade) | 6 MHz | 8 MHz | 10 MHz | 20 MHz | 10 MHz |
| Core Architecture | Z80 8-bit, 158 instructions | Z80 8-bit, 158 instructions | Z80 8-bit, 158 instructions | Z80 8-bit, 158 instructions | Z80 8-bit, 158 instructions | Z80 8-bit, 158 instructions |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Mounting | Through Hole (DIP) | Through Hole | Through Hole | Through Hole | Through Hole | Surface Mount (PLCC) |
| Lifecycle Status | EOL (last orders June 2024) | EOL | EOL | EOL | EOL | EOL |
| Interrupt Support | Mode 0/1/2 + NMI | Mode 0/1/2 + NMI | Mode 0/1/2 + NMI | Mode 0/1/2 + NMI | Mode 0/1/2 + NMI | Mode 0/1/2 + NMI |
Key Differentiators
- Highest speed grade in the family (vs Z84C0008PEG)
- CMOS low power versus original NMOS Z80 (vs Z8400 (NMOS Z80))
- Software-identical to original Z80 (vs Zilog eZ80)
Design Notes
The Z84C00 family is officially end-of-life (Zilog last-order deadline June 2024). Any new production BOM referencing this part carries unbounded supply risk. For sustaining designs, buy sufficient buffer stock now, qualify a second source (pin-compatible open-silicon Z80 clones for DIP-40, or an FPGA T80 soft-core for new boards), and document the migration path. Beware of counterfeit/remarked Z80s on the secondary market - the RC2014 community has documented NMOS Z80H parts sold as 20 MHz CMOS Z84C0020s that fail above 10 MHz.
The Z84C00 is a CMOS part requiring a single 5V supply; it is a direct power-savings substitute for the NMOS Z8400 in legacy sockets, drawing substantially lower static current. When replacing an NMOS Z80 in an old board, the reduced load can raise the 5V rail slightly on aged linear regulators - verify the rail stays within the CPU's specified tolerance. Unused CMOS inputs should not be left floating; tie them to VCC or GND through appropriate resistors to prevent shoot-through currents.
At 20 MHz (Z84C0020 grade), Z80 bus timing becomes tight: memory access cycles allow only a few clock periods for address setup, memory access, and data setup. Design or verify memory with access times that fit the datasheet AC timing for your clock grade, or use the WAIT input to stretch cycles for slower EPROM/flash or peripheral devices. Keep clock traces short with a clean, glitch-free clock source; the Z80 samples control signals on clock edges and a ringing clock can cause double-cycling. Decouple VCC with 100 nF ceramic directly at the package.
Compliance Information
Compliance data not present in the provided verified web data. Some Z84C00 suffix codes denote RoHS-compliant variants; verify per exact ordering code with Zilog documentation.
