NEC D8035 8-bit Single Chip Processor PDIP-40
The NEC D8035 8-bit Single Chip Processor PDIP-40 is an HMOS, parallel 8-bit microprocessor offered in a 40-pin PDIP package, designed for embedded control and microcomputer peripheral expansion. It implements the familiar 8-bit instruction set family, provides on-chip data RAM and I/O, an internal oscillator/clock generator and a programmable timer/event counter, and is intended to operate from a single +5VDC supply while using external program memory for code storage.
Features
- 8-bit HMOS CPU core with compact instruction set and efficient single-cycle instruction execution for many opcodes.
- Maximum operating frequency up to 6MHz for standard PDIP variants.
- 64×8 bits of internal data RAM for runtime data and stack usage.
- 27 programmable I/O lines arranged as two 8-bit ports and one 11/6-bit port for flexible interfacing.
- On-chip interval timer / event counter and test inputs for timing, counting and debug functions.
- Multiplexed address/data bus with ALE, RD, WR and PSEN control signals for interfacing to external program memory and peripherals.
- Internal clock generator with external crystal/resonator support for simple clocking.
- Single +5VDC supply operation with industry-standard TTL/MOS logic levels.
PINOUT

| No. | Symbol | Function |
|---|---|---|
| 1 | T0 | Test 0 input / output. |
| 2 | XTAL1 | Crystal 1 input. |
| 3 | XTAL2 | Crystal 2 input. |
| 4 | RESET | Reset input. |
| 5 | SS | Single step input. |
| 6 | INT | Interrupt input. |
| 7 | EA | External access input. |
| 8 | RD | Read output (or read strobe). |
| 9 | PSEN | Program store enable output. |
| 10 | WR | Write output (or write strobe). |
| 11 | ALE | Address latch enable output. |
| 12–19 | DB0–DB7 | Bidirectional data bus (AD0–AD7 / DB0–DB7). |
| 20 | VSS | Ground. |
| 21–24, 35–38 | P2₀–P2₇ | Quasi-bidirectional Port 2. |
| 25 | PROG | Program output. |
| 26 | VDD | RAM power supply. |
| 27–34 | P1₀–P1₇ | Quasi-bidirectional Port 1. |
| 39 | T1 | Test 1 input. |
| 40 | VCC | Primary power supply (+5 V). |
Specifications
| Parameter | Value |
|---|---|
| Core | 8-bit HMOS CPU. |
| Max Frequency | 6MHz. |
| Internal RAM | 64×8bits. |
| Program Memory | External (no internal ROM). |
| I/O Ports | 27 lines (2×8bit ports + additional control/PC lines). |
| Timer Counter | On-chip 8-bit interval timer / event counter. |
| Address Data Bus | Multiplexed AD0–AD7 with ALE, RD, WR, PSEN control. |
| Supply Voltage | +5VDC. |
| Operating Temp | 0°C to +70°C |
| Package | 40-pin PDIP. |
| Power Dissipation | Typical operating currents and DC characteristics per datasheet. |
Note: for full specifications, check the datasheet at the end of the page.
Applications
- External program-memory systems and legacy 8-bit microcomputer designs.
- Embedded controllers for appliances, instrumentation and industrial control.
- I/O expansion and simple data-acquisition front ends.
- Educational, hobbyist and repair use where DIP packaging and 8080/8085-style bus compatibility are required.
Package Contents
- 1x NEC D8035 8-bit Single Chip Processor PDIP-40.
Documents
| Datasheet | D8035 |
