Renesas HD64F3687FP

Overview

HD64F3687FP from Renesas Electronics is a 16-bit single-chip microcomputer in the H8/300H Tiny Series, featuring an H8/300H CPU core with H8/300 instruction set compatibility, 64 KB on-chip ROM, 4 KB RAM, and integrated peripherals including UART (SCI), timer modules (8-bit and 16-bit), and 32 I/O pins. It operates at up to 20 MHz and targets embedded control applications requiring compact footprint and low-power operation.

For engineers reviewing the HD64F3687FP datasheet, HD64F3687FP pinout, HD64F3687FP application, or HD64F3687FP equivalent, key selection considerations include its 80-pin PQFP package, 5 V operation, on-chip ROM execution capability, and support for sleep/standby power-down modes in resource-constrained industrial and consumer systems.

Technical Context

The HD64F3687FP implements the H8/300H CPU architecture with 24-bit addressing, supporting both byte- and word-aligned memory access. Its system clock generator accepts crystal (1–20 MHz), ceramic resonator, or external clock input, and includes independent subclock circuitry for real-time clock functions using a 32.768 kHz source.

Peripheral integration includes two 8-bit timers (TMR0/TMR1), one 16-bit timer (TMR2), three serial communication interfaces (SCI0–SCI2), and a 10-channel 10-bit A/D converter. Memory-mapped I/O and interrupt vectoring are implemented via fixed-address exception handling with priority-based nested interrupts.

Key Specifications

Pinout & Package

HD64F3687FP is housed in an 80-pin Plastic Quad Flat Package (PQFP) with 0.65 mm lead pitch, compliant with JEDEC MS-026. The package supports surface-mount assembly and provides thermal dissipation suitable for industrial ambient temperatures (−20°C to +75°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit microcontroller applications.

Compared with HD64F3684FP and HD64F3694FP, the HD64F3687FP balances memory capacity, analog acquisition capability, and serial interface count for mid-tier embedded control-offering full feature coverage without CAN overhead or memory reduction.

Availability

HD64F3687FP is available at Aetrix Electronics and suitable for industrial motor control, home appliance UI, point-of-sale terminals, and building automation sensor nodes requiring stable component supply and long-term production support.

Supply support for HD64F3687FP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics Corporation is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, power, and SoC solutions for industrial, automotive, and IoT markets.

The H8/3687 Group, including HD64F3687FP, was designed for cost-sensitive, low-to-mid complexity embedded control applications demanding high integration, low power, and robust real-time performance in consumer and industrial equipment.

FAQ

What is the maximum operating frequency of the HD64F3687FP?

The HD64F3687FP supports a maximum system clock frequency of 20 MHz when using an external crystal or resonator. This frequency enables approximately 12.5 million instructions per second (MIPS) throughput, sufficient for real-time control tasks such as motor commutation, sensor polling, and protocol parsing. The device's internal clock generator includes prescalers and dividers to derive peripheral clocks from this master frequency, and timing specifications in the datasheet confirm stable operation across the full range under specified VCC and temperature conditions.

Does the HD64F3687FP include on-chip flash or EEPROM memory?

No, the HD64F3687FP features 64 KB of mask-programmed ROM, not flash or EEPROM. This means firmware is permanently written during manufacturing and cannot be field-updated. For development, Renesas recommends using the on-chip emulator (E7/E8) via dedicated debug pins (P85–P87) or boot-mode programming through SCI. Mask ROM ensures immunity to accidental overwrite and provides deterministic boot behavior, making HD64F3687FP appropriate for high-volume, unchanging firmware deployments like appliance controllers.

How many serial communication interfaces does the HD64F3687FP support?

The HD64F3687FP integrates three independent Serial Communication Interfaces (SCI0, SCI1, SCI2), each supporting asynchronous full-duplex UART operation with programmable baud rates, parity, and stop bits. SCI0 and SCI1 share pins with Port 0 and Port 1 respectively, while SCI2 uses Port 2 pins. All three SCIs can operate concurrently, enabling simultaneous communication with multiple peripherals - for example, SCI0 for host debugging, SCI1 for sensor telemetry, and SCI2 for actuator command reception - without software arbitration or external multiplexing.

What power-saving modes are available on the HD64F3687FP?

The HD64F3687FP offers four hardware-supported low-power modes: Sleep, Standby, Subsleep, and Subactive. In Standby mode, CPU and most peripherals halt while RAM and certain wakeup sources (e.g., external interrupt, SCI receive) remain active, drawing as little as 10 µA. Subsleep retains the subclock domain for RTC operation. These modes are controlled via SYSCR1/SYSCR2 registers and entered using the STOP instruction. Each mode has defined wakeup latency and retained resources, allowing precise trade-offs between responsiveness and energy consumption in battery-powered or thermally constrained designs.

Is the HD64F3687FP pin-compatible with other devices in the H8/3687 Group?

Yes, the HD64F3687FP shares the same 80-pin PQFP package and pin assignment with other members of the H8/3687 Group, including HD64F3684FP and HD64N3687G. Pin compatibility extends to power, clock, reset, and all I/O and peripheral signal locations. However, functional differences exist - for example, HD64F3684FP lacks SCI2 and has fewer A/D channels - so firmware and PCB design must verify peripheral usage matches the selected variant. This pin alignment simplifies hardware platform reuse across product tiers with varying feature sets.