Renesas HD64F3694HJ

Overview

HD64F3694HJ from Renesas Technology Corp. is a 16-bit single-chip microcomputer in the H8/3694 Group, featuring the H8/300H CPU core, 128 KB on-chip Flash ROM, 8 KB RAM, and integrated peripherals including Timer A, Timer V, and multiple I/O ports. It operates at up to 20 MHz and supports multiple power-down modes (Sleep, Standby, Subsleep) for embedded control in industrial and consumer applications.

For engineers reviewing the HD64F3694HJ datasheet, HD64F3694HJ pinout, HD64F3694HJ application, or HD64F3694HJ equivalent, key selection criteria include its 128 KB Flash memory size, 20 MHz max CPU frequency, 80-pin PQFP package, support for on-board programming, and compatibility with the H8/300H instruction set architecture.

Technical Context

The HD64F3694HJ implements the H8/300H CPU core - a 16-bit CISC architecture with full instruction set compatibility to the earlier H8/300 - and integrates system-control modules (clock generators, power-down controllers), on-chip Flash memory with erase/program capability, and peripheral modules including two independent timers (Timer A and Timer V) with flexible output modes and interrupt sources.

It features dual clock domains: a main system clock (up to 20 MHz via crystal, ceramic resonator, or external clock) and a 32.768 kHz subclock for real-time functions; supports four low-power modes with configurable module standby; and provides 80 I/O pins across Ports 1, 2, 5, 7, 8, and Port B, with programmable pull-up, data direction, and control registers per port.

Key Specifications

Pinout & Package

HD64F3694HJ is housed in an 80-pin Plastic Quad Flat Package (PQFP) with 0.65 mm lead pitch, designed for high-density PCB layouts and standard reflow soldering processes.

Key Features

Applications

Equivalent & Alternatives

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

Compared with HD64F3694HJ, HD64F3687FV offers reduced memory and I/O for compact designs, while HD64F3692HJ trades programmability for ROM-based reliability - both require evaluation against firmware size, update requirements, and peripheral needs.

Availability

HD64F3694HJ is available at Aetrix Electronics and suitable for industrial motor control, consumer appliance UI, smart energy metering, and building automation node applications requiring stable component supply and long-term lifecycle support.

Supply support for HD64F3694HJ 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 Technology Corp. (now part of Renesas Electronics Corporation) is a Japanese semiconductor manufacturer specializing in microcontrollers, analog, and power devices for industrial, automotive, and consumer markets.

The H8/3694 Group - including HD64F3694HJ - was designed for cost-sensitive, low-to-medium complexity embedded control applications demanding reliable Flash-based firmware execution, flexible timing, and low-power operation.

FAQ

What is the maximum operating frequency of the HD64F3694HJ?

The HD64F3694HJ supports a maximum CPU operating frequency of 20 MHz when driven by an external crystal, ceramic resonator, or clock source connected to the XIN/XOUT pins. This frequency determines instruction execution speed and real-time peripheral response - for example, Timer A's interval resolution scales inversely with system clock rate. The HD64F3694HJ achieves this performance while maintaining full H8/300H instruction set compatibility and low power consumption in active mode.

Does the HD64F3694HJ support in-system programming?

Yes, the HD64F3694HJ supports on-board programming via two distinct modes: boot mode (using dedicated serial interface pins) and user program mode (executing Flash write/erase routines from RAM). This capability allows firmware updates without removing the device from the target board. The HD64F3694HJ includes hardware and software protection mechanisms - such as FLMCR1 register locks and erase-block security bits - to prevent unintended or malicious reprogramming during normal operation.

What power-down modes are available on the HD64F3694HJ?

The HD64F3694HJ implements four configurable power-down modes: Sleep (CPU stopped, clocks active), Standby (main clock stopped, subclock active), Subsleep (subclock active, RAM retained), and Subactive (subclock active, selected modules operational). Each mode is controlled via SYSCR1/SYSCR2 registers and enables precise trade-offs between wakeup latency and current draw - for instance, Subsleep draws under 10 µA while preserving RTC functionality. The HD64F3694HJ's power management architecture makes it suitable for battery-powered metering and sensor nodes.

Is the HD64F3694HJ pin-compatible with other H8/3694 family members?

Yes, the HD64F3694HJ in its 80-pin PQFP package shares identical pinout with other H8/3694 variants including HD64F3692HJ and HD64F3694G. This allows direct substitution in existing PCB layouts when upgrading memory capacity or enabling on-board programming - provided firmware and configuration registers are updated accordingly. However, functional differences (e.g., Flash size, programming support) must be verified in software; the HD64F3694HJ's 128 KB Flash and full programming capability distinguish it from ROM-only or lower-memory variants.

What development tools are supported for the HD64F3694HJ?

The HD64F3694HJ is supported by Renesas' legacy H8 toolchain, including the H8S/H8/300 Series C/C++ Compiler (ADE-702-247), Simulator/Debugger (ADE-702-282), and High-Performance Embedded Workshop IDE. Hardware debugging uses the E10T on-chip emulator (with known restrictions: NMI pin reserved, P85–P87 unavailable, and memory regions H'7000–H'7FFF and H'F780–H'FB7F off-limits). The HD64F3694HJ's compatibility with these mature tools ensures stable firmware development for long-lifecycle industrial applications.