Z86C9333FSC - 33MHz 8-Bit ROMless MCU | Zilog
MPN: Z86C9333FSC ✓ ActiveZ86C9333FSC Overview
An 8-bit microcontroller is a compact processor designed to execute embedded control logic from program memory and maintain operating state in RAM. The Z86C9333 belongs to the broader embedded-controller hierarchy: MCU -> microcontroller -> embedded processor -> semiconductor. A ROMless architecture means the device contains no internal program ROM, so firmware must be supplied through an external memory interface. This architecture is useful when programs, firmware revisions, or memory sizes must remain flexible.
The verified feature set includes ROMless operation at 33 MHz, 236 bytes of RAM, 24 I/O lines, three 8-bit timers, UART communication, and EBI/EMI interfaces. The 44-LQFP surface-mount package exposes substantially more signal pins than small dual-inline packages, supporting parallel external memory and additional peripheral connectivity while remaining compatible with automated PCB assembly.
The Z86C9333 architecture is intended for embedded control rather than high-compute workloads. Its external program-memory interface allows the stored firmware size to be established outside the MCU, while its three timers support periodic counting, timing, and event generation. UART/USART communication enables connection to host systems, sensors, or other controllers, and EBI/EMI provides an external bus-oriented path for additional devices.
Typical applications include industrial keypad controllers, serial data concentrators, instrumentation interfaces, embedded control panels, and compact automation modules. In these systems, the 33 MHz speed can improve response to serial traffic and control tasks, while the 24 I/O lines reduce the need for separate I/O expanders. The ROMless configuration is particularly valuable when the same MCU platform must cover several firmware versions or board configurations.
Designers must account for external program-memory timing, address decoding, bus contention, and required support components when using the ROMless configuration. PCB layout should minimize routing delay and preserve signal integrity on external bus and UART lines. Software must also provide the vector table and reset behavior expected by the external memory system. Because the verified data does not state supply voltage, timing margins, or detailed pin assignments, those values should be confirmed in the manufacturer documentation before schematic capture.
This product page consolidates verified distributor specifications, same-package replacement information, application guidance, and design cautions. It distinguishes confirmed Z86C9333FSC characteristics from unavailable electrical details so procurement and engineering decisions can be made without inventing package, pin, or lifecycle information.
Drop-in alternatives for Z86C9333FSC — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Z86C9333FSG
✅ Drop-In📋 Reference alternative (not in catalog)
Z86C9333FEC
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
Z86C9333FSC
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →Z86C9333FSC Maximum Ratings & Electrical Characteristics
| CPU Architecture | 8-bit Z8 |
| Maximum Clock Speed | 33 MHz |
| Program Memory Architecture | ROMless |
| Internal RAM | 236 x 8 bytes |
| General-Purpose I/O | 24 I/O |
| 8-Bit Timers | 3 timers |
| Serial Interface | UART/USART |
| External Bus Interface | EBI/EMI |
| Supported Speed Options | 20 MHz, 25 MHz, 33 MHz |
| Package Type | 44-pin LQFP |
| Package Dimensions | 10 x 10 mm |
| Mounting Type | Surface Mount |
Z86C9333FSC 10 x 10 mm Pin Configuration Guide
Pin configuration for Z86C9333FSC (10 x 10 mm package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for Z86C9333FSC.
Refer to the datasheet for full pin configuration.
Typical Applications
Z86C9333FSC is suitable for 6 applications: Industrial Control Panels, Instrumentation and Data Concentrators, Serial Communication Hubs, Programmable Automation Modules, Embedded Communication Bridges, Compact Measurement Systems.
Industrial Control Panels
The Z86C9333FSC fits industrial control-panel designs because its 33 MHz Z8 CPU provides responsive control processing while 24 I/O lines support keys, indicators, relays, and discrete sensors. The three 8-bit timers can organize periodic tasks, debouncing, and timing sequences, and the ROMless architecture allows firmware versions to follow changes in external memory. For a panel with several boards, UART/USART can connect a supervisory controller while EBI/EMI provides an external bus path. The key engineering trade-off is the added external program-memory design effort, but it provides flexibility when product configurations or firmware revisions differ.
Recommended
Instrumentation and Data Concentrators
The Z86C9333FSC is suitable for instrumentation and data-concentrator functions that combine local control with serial data transfer. Its UART/USART interface can communicate with sensors, converters, or host equipment, while 236 x 8 bytes of RAM supports protocol buffering and temporary data processing. The 33 MHz clock allows the firmware to service communication and control tasks more responsively than a low-speed 8-bit MCU. Because the device is ROMless, its external program memory can be selected to match firmware size and update requirements. Designers should verify external-bus timing and UART electrical levels against the exact system architecture.
Recommended
Serial Communication Hubs
The Z86C9333FSC can serve as the controller in a compact serial communication hub where several local nodes must be coordinated. The confirmed UART/USART capability provides the fundamental serial channel, the 33 MHz operating speed supports responsive protocol handling, and the EBI/EMI interface can connect external memory or bus-oriented peripherals. Its 24 I/O lines can provide indicators, configuration inputs, and fault signaling without requiring a large FPGA. The ROMless implementation is advantageous when several firmware variants share one board, although designers must budget correctly for external program memory and ensure reset and bus contention behavior are deterministic.
Recommended
Programmable Automation Modules
The Z86C9333FSC is appropriate for programmable automation modules that combine timing, discrete I/O, and serial coordination. Its three 8-bit timers support repeating intervals, pulse generation, and event counting, while 24 I/O lines can connect sensors, actuators, and status LEDs. At 33 MHz, the controller has additional throughput for executing a control state machine and communication stack. The ROMless architecture permits program storage to be scaled independently of the MCU, which can be useful across a family of modules. A practical design must include external memory, deterministic reset behavior, suitable decoupling, and careful signal routing for the external bus.
Recommended
Embedded Communication Bridges
The Z86C9333FSC can implement an embedded bridge between a legacy serial device and a more modern embedded controller. UART/USART handles the serial endpoint, the 33 MHz CPU can process framing and protocol translation, and EBI/EMI supports external memory or peripheral expansion. Its 24 available I/O lines are useful for mode controls, status signals, and interface selection. Selecting ROMless external memory allows one controller platform to support several firmware configurations or field-update arrangements. The principal limitation is that software and external-memory timing must be validated carefully, particularly during reset, bus contention, and communication error recovery.
Recommended
Compact Measurement Systems
The Z86C9333FSC suits compact measurement systems requiring local control, timing, and serial reporting. Three 8-bit timers can support sampling schedules, measurement intervals, and timeout functions, while the 24 I/O lines can operate sensor enables, range selection, and status indicators. The 236-byte RAM provides working storage for calibration values and short data frames, while the 33 MHz CPU handles measurement sequencing and UART-based reporting. The ROMless architecture permits external program-memory sizing according to the instrument configuration. Before deployment, engineers should verify ADC or sensor interfaces, input thresholds, supply voltage, and environmental limits from the complete manufacturer documentation.
Recommended
Recommended Products Summary
Engineering reference data for Z86C9333FSC — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | Z86C9333FSG | Z86C9333FEC | Z86C9333FSC |
|---|---|---|---|---|
| Brand | Zilog | Zilog | Zilog | Zilog |
| Package | 44-LQFP (10 x 10 mm) | 44-LQFP - same | 44-LQFP - same | 44-LQFP - same |
| CPU Architecture | 8-bit Z8 | 8-bit Z8 | 8-bit Z8 | 8-bit Z8 |
| Maximum Clock Speed | 33 MHz | 33 MHz | 33 MHz | 33 MHz |
| Program Memory | ROMless | ROMless | ROMless | ROMless |
| Internal RAM | 236 x 8 bytes | 236 x 8 bytes | 236 x 8 bytes | 236 x 8 bytes |
| General-Purpose I/O | 24 I/O | 24 I/O | 24 I/O | 24 I/O |
| Serial and External-Bus Interfaces | UART/USART and EBI/EMI | UART/USART and EBI/EMI | UART/USART and EBI/EMI | UART/USART and EBI/EMI |
| 8-Bit Timers | 3 timers | 3 timers | 3 timers | 3 timers |
Key Differentiators
- 33 MHz execution within an 8-bit Z8 controller (vs ATMEGA328P-MNR)
- Flexible ROMless program-memory architecture (vs Z86C9333FSG)
- Three timers and 24 I/O lines in one 44-LQFP device (vs ATMEGA328P-MNR)
Design Notes
Do not treat the ROMless designation as a missing feature that can be ignored. The design must include external program memory, address decoding, and a reset arrangement that presents valid instruction-fetch behavior to the Z8 CPU. Before schematic capture, confirm the required memory size, bus timing, and access protocol in the manufacturer documentation. A working substitute also requires that its external-memory and reset behavior remain identical to the original device.
Place external program memory and its decoupling close to the corresponding Z86C9333FSC pins, and route address, data, and control lines with short, continuous paths. Avoid adding test-point stubs or long serpentine sections on high-frequency external-bus signals. Because the device supports operation up to 33 MHz, preserve controlled return paths and avoid sharing noisy switching-current routes with the external memory interface.
Verify the exact supply-voltage range and input-current limits before selecting decoupling and power-conversion components; those values are not stated in the supplied distributor results. Follow the manufacturer recommendations for input and output capacitance, and keep the regulator or supply rail quiet enough for the external program-memory interface. Treat any power-dissipation or capacitor-selection calculation as an estimate until the complete electrical characteristics are available.
The UART/USART and EBI/EMI interfaces should be reviewed as potentially coupled communication paths rather than isolated general-purpose logic. Keep clock-sensitive traces away from switching nodes and noisy serial return currents, and provide a continuous ground reference. If the board supports an external memory device or expansion bus, confirm setup and hold timing, output-enable behavior, and bus contention handling using the exact package and suffix documentation.
Compliance Information
The supplied distributor results do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. These fields remain unknown rather than being inferred from the Zilog brand or package suffix.
