## Technical Overview: Z0803606LED (Z8036 Z-CIO) The **Z0803606LED** is a specific variant of the Zilog **Z8036 Z-CIO** (Counter/Timer and Parallel I/O) integrated circuit. It is a versatile peripheral device designed to provide input/output capabilities and timing functions for 8-bit and 16-bit microprocessor systems, specifically optimized for the Z-BUS architecture. --- ### 1. Part Number Breakdown Understanding the suffix and prefix is crucial for identifying its physical and electrical characteristics: | Part Segment | Meaning | | :--- | :--- | | **Z08036** | The base model number for the Z-CIO (Counter/Timer and Parallel I/O). | | **06** | **Clock Speed:** 6 MHz maximum operating frequency. | | **L** | **Package Type:** PLCC (Plastic Leaded Chip Carrier). | | **E** | **Temperature Range:** Extended temperature (-40°C to +100°C). | | **D** | **Environmental:** Often denotes Lead-Free/RoHS compliance (standard in newer Zilog parts). | --- ### 2. Key Internal Components The Z8036 acts as a "Swiss Army Knife" for I/O interfacing. It contains three main functional blocks: #### A. Parallel I/O Ports * **Two 8-bit Ports (Port A and B):** Can be configured as input, output, or bidirectional. They include handshake lines for asynchronous data transfers. * **One 4-bit Port (Port C):** Usually serves as a handshake control for Ports A and B or as general-purpose I/O. #### B. Counter/Timer Channels * Contains **three 16-bit counter/timers**. * Each counter has its own external clock input, gate input, and output. * Supports various modes: retriggerable, one-shot, and square wave generation. #### C. Interrupt Logic * Features a sophisticated interrupt structure common to Zilog parts (Z-BUS). * Supports **Interrupt Vectoring**, allowing the CPU to jump directly to the service routine for a specific I/O event. --- ### 3. Technical Specifications | Parameter | Value | | :--- | :--- | | **Supply Voltage (Vcc)** | 5V ± 5% | | **Max Clock Frequency** | 6 MHz | | **I/O Pins** | 20 Programmable I/O lines | | **Counters** | Three 16-bit units | | **Bus Interface** | Z-BUS (Multiplexed Address/Data) | | **Package** | 44-pin PLCC | --- ### 4. Typical Applications The Z0803606LED is commonly found in legacy industrial controllers and embedded systems that require: 1. **Event Counting:** Counting external pulses (e.g., from an optical encoder). 2. **Frequency Generation:** Creating precise PWM signals or baud rate clocks. 3. **Complex Interfacing:** Connecting a Z80, Z8000, or similar CPU to keyboards, printers, or sensors. --- ### 5. Programming Interface To use the Z-CIO, you must interact with its internal registers. The programming model includes: * **Direct Register Access:** Using the multiplexed address/data bus. * **Mode Specification Registers:** Used to define if a port is bit-programmable or handshaked. * **Command/Status Registers:** Used to start/stop timers or check the status of I/O lines.