Renesas HD4074054S

Overview

HD4074054S from Renesas Electronics is a 4-kword ZTAT™ PROM-based 4-bit microcontroller in the HMCS400 family, featuring three timer/counters, one clock-synchronous 8-bit serial interface, dual-channel comparator, and input capture circuitry. It operates with 1 µs instruction cycle time at 4 MHz system clock (1/4 division), supports MCU/PROM mode, and targets embedded control applications requiring field-programmable firmware with zero-turnaround-time development.

For engineers reviewing the HD4074054S datasheet, HD4074054S pinout, HD4074054S application, or HD4074054S equivalent, key selection considerations include its DP-42S 42-pin plastic DIP package, 10-mA source / 15-mA sink I/O capability on dedicated pins, PROM programmability via standard 27256-compatible writers, and dual low-power modes (standby/stop) with external wake-up support.

Technical Context

The HD4074054S implements a Harvard-architecture 4-bit CPU with 14-bit program counter, 512 × 4-bit RAM, and 4,096 × 10-bit PROM. Its memory map includes vector address area ($0000–$000F), zero-page subroutine space ($0000–$003F), and 4-kword program area ($0000–$0FFF).

It integrates peripheral blocks including Timer A (event counter with double-edge detection), Timer C and D (with PWM outputs), Serial Interface 1 (SCK1/SI1/SO1), two analog comparators (COMP0/COMP1), and an 8-bit input capture circuit tied to R4/EVND. System clock division is selectable (1/4 or 1/32) via SEL pin.

Key Specifications

Pinout & Package

HD4074054S uses the DP-42S 42-pin plastic dual in-line package (DIP), 0.6-inch width, with 0.1-inch pin pitch and through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 4-bit microcontroller applications.

Compared with HD404054S, HD4074054S trades mask ROM permanence for field-programmability and faster iteration, while HD4074094S shifts I/O capability toward higher-voltage drive at the expense of 5-V source/sink count - making HD4074054S the optimal choice for cost-sensitive, firmware-evolving 5-V embedded controls.

Availability

HD4074054S is available at Aetrix Electronics and suitable for industrial motor control, appliance user interface, energy metering subsystems, and automated test equipment fixtures requiring stable component supply across extended product lifecycles.

Supply support for HD4074054S 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 HD4074054S belongs to the HMCS400-series microcontroller product line, designed specifically for cost-sensitive, low-pin-count embedded control applications where PROM-based flexibility, integrated peripherals, and ultra-low-power operation are essential.

FAQ

What is the programming method for the HD4074054S PROM?

The HD4074054S uses a ZTAT™ (Zero Turn Around Time) PROM that is programmed externally using a standard 27256-compatible PROM writer. Programming occurs before soldering or via socketed programming; it does not support in-circuit reprogramming. The PROM is one-time programmable and retains data without power. HD4074054S firmware must be fully verified prior to programming, as no field updates are possible after write completion.

Does the HD4074054S support in-system debugging?

No, the HD4074054S does not include on-chip debug interfaces such as JTAG or SWD. Debugging is performed using external emulators compatible with the HMCS400 architecture or by leveraging the TEST pin and RESET-based entry into test mode - which is reserved for factory use only. Engineers must rely on serial interface logging, GPIO toggling, and RAM inspection via external tools during development. HD4074054S design validation requires careful pre-load firmware testing.

What are the voltage requirements for the VCref pin on the HD4074054S?

The VCref pin on the HD4074054S accepts an external reference voltage ranging from 0 V to VCC (typically 5 V). This voltage sets the comparison threshold for both COMP0 and COMP1 analog inputs. The pin has no internal regulation or buffering; therefore, a clean, low-impedance source (e.g., precision voltage divider or bandgap reference) is required to ensure stable comparator operation. Noise on VCref directly impacts comparator accuracy and repeatability in HD4074054S-based sensing applications.

Can the HD4074054S operate from a 3.3 V supply?

No, the HD4074054S is specified for operation only at VCC = 5.0 V ±10% (4.5 V to 5.5 V). Its internal oscillator, I/O drive strength, and comparator input ranges are characterized exclusively for 5-V operation. Using 3.3 V will result in undefined behavior, including failure to execute instructions, incorrect I/O states, and unreliable analog comparisons. For 3.3-V systems, designers must use level-shifting or select a modern 3.3-V-compatible microcontroller - HD4074054S is not suitable.

How many interrupt sources does the HD4074054S support, and how are they configured?

The HD4074054S supports six interrupt sources: two external (INT0, INT1), and four internal (Timer A overflow, Timer C overflow, Timer D overflow, Serial Interface 1 transfer complete). Each interrupt has a dedicated mask (IMx) and flag (IFx) bit located in RAM addresses $000–$003. Configuration is performed by writing to these RAM-mapped registers using SEM/SEMD or TM/TMD instructions. Interrupt priority is fixed in hardware order, with INT0 having highest priority and Serial Interface 1 lowest.