Renesas DF38076RH4V

Overview

DF38076RH4V from Renesas Electronics is a 16-bit single-chip microcomputer in the H8/300H Super Low Power Series, featuring an H8/300H CPU core with H8/300 instruction set compatibility, 52 KB on-chip ROM, 4 KB RAM, and integrated peripherals including TPU (16-bit timer pulse unit), SCI (serial communication interface), and RTC. It operates at up to 20 MHz and supports multiple low-power modes (subactive, subsleep, standby) for battery-powered industrial control and sensor interface applications.

For engineers reviewing the DF38076RH4V datasheet, DF38076RH4V pinout, DF38076RH4V application, or DF38076RH4V equivalent, key selection criteria include its 80-pin TQFP package (12 × 12 mm, 0.5 mm pitch), flash memory version compatibility, on-chip debugging emulator support (E7), and subclock generator capability for 32.768-kHz real-time clock operation.

Technical Context

The DF38076RH4V implements a Harvard-architecture H8/300H CPU with 24-bit address space, supporting both medium-speed (φM) and high-speed (φH) system clocks derived from external crystal (e.g., 4.19 MHz) or on-chip oscillator. Its interrupt controller provides three mask levels via IPRA–IPRE registers and handles 25 internal interrupts (flash version) plus external IRQ/NMI inputs.

Power management includes dedicated clock halt registers (CKSTPR1/2) enabling per-module standby control - e.g., FROMCKSTP disables flash memory clock, TFCKSTP halts Timer F - while SYSCR1/2 configure oscillation stabilization wait time, subclock sampling frequency (NESEL), and subactive/subsleep clock division (SA1/SA0).

Key Specifications

Pinout & Package

DF38076RH4V is housed in a 80-pin Thin Quad Flat Package (TQFP) with 0.5 mm lead pitch and 12 mm × 12 mm body size (package code PTQP0080KC-A). Pin functions are defined across four I/O ports (P1–P4), with dedicated signals for timer I/O (TIOCA1/TIOCB1), serial interfaces (SCI3/SCI4), reset (RES), and subclock (X1/X2).

Key Features

Applications

Equivalent & Alternatives

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

Compared with DF38076RH4V, R5F38076KFP offers identical functionality in a larger-package variant, while H8/38075R trades memory and peripheral capacity for lower unit cost - neither is pin-to-pin compatible due to differing package codes and internal feature gating.

Availability

DF38076RH4V is available at Aetrix Electronics and suitable for industrial sensor nodes, smart meter interfaces, PLC I/O modules, and medical diagnostic handhelds requiring stable component supply across extended production lifecycles.

Supply support for DF38076RH4V 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 global semiconductor leader specializing in microcontrollers, analog, and power devices for industrial, automotive, and infrastructure markets.

The H8/38076R Group belongs to Renesas' legacy 16-bit H8 Family, designed specifically for ultra-low-power embedded control in resource-constrained environments where long battery life and deterministic real-time response are critical.

FAQ

What is the maximum operating frequency of the DF38076RH4V?

The DF38076RH4V supports a maximum system clock frequency of 20 MHz when driven by an external crystal oscillator or high-speed on-chip source. This frequency enables real-time execution of control algorithms and serial communication at standard baud rates up to 115.2 kbps. The actual achievable speed depends on supply voltage (2.7–5.5 V) and ambient temperature, with full 20 MHz operation guaranteed across the industrial temperature range (−40°C to +85°C) at VCC ≥ 4.5 V.

Does the DF38076RH4V include on-chip flash memory?

No, the DF38076RH4V is a ROM-based variant with 52 KB of mask-programmed on-chip ROM, not user-reprogrammable flash memory. It belongs to the "masked ROM version" of the H8/38076R Group, intended for high-volume, fixed-function applications where firmware is finalized before production. For flash-based alternatives, consider the H8/38076RF series, which shares the same pinout and peripheral set but replaces ROM with reprogrammable flash.

How does the DF38076RH4V manage power in battery-operated systems?

The DF38076RH4V implements three hierarchical low-power states: subactive (CPU halted, peripherals active), subsleep (subclock domain active, RAM retained), and standby (only RTC and wake-up logic powered). In subsleep mode with 32.768-kHz crystal, current consumption drops below 2 μA while preserving RTC time and 4 KB RAM contents. Wake-up sources include external interrupts (IRQ0–IRQ4, WKP0–WKP7) and serial activity on SCI3/SCI4, enabling responsive yet energy-efficient operation.

Can the DF38076RH4V be debugged without external hardware?

Yes, the DF38076RH4V integrates an on-chip debugging emulator (E7) that eliminates the need for external JTAG probes. Debugging is performed via dedicated pins (NMI, P16, P36, P37) and internal memory regions (H'C000–H'CFFF), allowing breakpoints, register inspection, and real-time variable monitoring. However, these pins are reserved during debug sessions, so application firmware must avoid using them for general I/O when debugging is active.

What crystal specifications are required for the DF38076RH4V subclock input?

The DF38076RH4V subclock input (X1/X2) requires a 32.768-kHz or 38.4-kHz tuning-fork crystal resonator with ≤35 kΩ equivalent series resistance (ESR) and 7 pF load capacitance. Epson Toyocom C-001R (32.768 kHz) and C-4-TYPE (38.4 kHz) are validated options. Exceeding the ESR limit may cause start-up failure or timing inaccuracy in watch mode, especially at low temperatures or after extended storage.