High-Speed, 8-Bit, Single-Chip Hmos Microcomputers The part **UPD8749HD** is a microcontroller manufactured by **NEC**. Below are the specifications, descriptions, and features based on available information:
### **Specifications:**
- **Manufacturer:** NEC (now part of Renesas Electronics)
- **Part Number:** UPD8749HD
- **Type:** 8-bit Microcontroller
- **Architecture:** MCS-48 family (Intel-compatible)
- **CPU Core:** 8048-compatible
- **Clock Speed:** Typically operates at **6 MHz** (varies by model)
- **Program Memory (ROM):** 2 KB (2048 bytes)
- **Data Memory (RAM):** 128 bytes
- **I/O Ports:** 27 programmable I/O lines
- **Timers/Counters:** 8-bit timer/counter
- **Interrupts:** Single-level interrupt system
- **Operating Voltage:** **5V DC** (standard for MCS-48 family)
- **Package:** **40-pin DIP (Dual In-line Package)**
### **Descriptions:**
The **UPD8749HD** is an 8-bit microcontroller from NEC, part of the **MCS-48 family**, which is compatible with Intel’s 8048 architecture. It integrates **ROM, RAM, and I/O ports** in a single chip, making it suitable for embedded control applications.
### **Features:**
- **8-bit CPU** with efficient instruction set (96 instructions)
- **On-chip 2KB ROM** for program storage
- **128 bytes of RAM** for data storage
- **27 I/O lines** for interfacing with peripherals
- Built-in **8-bit timer/counter**
- **Single-level interrupt** support
- **Low-power consumption** (typical for 5V CMOS microcontrollers)
- **40-pin DIP package** for easy integration
This microcontroller was commonly used in **industrial control systems, consumer electronics, and early embedded applications**.
(Note: Some details may vary depending on specific variants or datasheet revisions.)
