Renesas 7007S55J

Overview

7007S55J from IDT (Integrated Device Technology) is a high-speed 32K × 8 dual-port static RAM with true independent left/right ports, 55 ns maximum read cycle time (tRC), 5 V ±10% single-supply operation, and integrated hardware semaphore/arbiter logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 7007S55J datasheet, 7007S55J pinout, 7007S55J application, or 7007S55J equivalent, this device supports simultaneous asynchronous access to shared memory, on-chip BUSY arbitration, interrupt flag signaling, and master/slave cascading for 16-bit+ data bus expansion - critical for industrial motion controllers, avionics data concentrators, and redundant telecom switching modules.

Technical Context

The 7007S55J implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port (A0L–A14L/I/O0L–I/O7L and A0R–A14R/I/O0R–I/O7R), enabling concurrent read/write operations without external logic. Its on-chip arbitration logic resolves contention via BUSY flag assertion (push-pull, not open-drain) and M/S pin configuration.

It supports two distinct memory access modes: standard RAM access (CE = LOW, SEM = HIGH) and semaphore register access (CE = HIGH, SEM = LOW), with dedicated 3-bit address decoding (A0–A2) for eight semaphore flags. Interrupts are triggered by writes to fixed addresses 7FFE_H (INTL) and 7FFF_H (INTR), cleared by subsequent reads.

Key Specifications

Pinout & Package

7007S55J is packaged in an 80-pin thin quad flatpack (TQFP), body size 14 mm × 14 mm × 1.4 mm, with 0.5 mm pitch and exposed thermal pad (not electrically connected). All VCC pins require local decoupling; all GND pins must be solidly tied to system ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-port SRAM applications.

Compared with CY7C028V-55AC and AS7C33256P-55JC, the 7007S55J uniquely integrates full hardware semaphore, interrupt flag, and master/slave cascading in a drop-in 80-pin TQFP package - reducing BOM count, PCB area, and firmware complexity in tightly coupled multi-processor systems.

Availability

7007S55J is available at Aetrix Electronics and suitable for industrial motion control, avionics data concentrators, and telecom line card switching requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 7007S55J 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

IDT (Integrated Device Technology) was a fabless semiconductor company specializing in high-performance timing, memory, and interface solutions before its acquisition by Renesas Electronics in 2019.

The IDT7007 family was designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, interrupt signaling, and seamless master/slave scalability without external logic.

FAQ

What is the maximum operating frequency supported by the 7007S55J?

The 7007S55J does not operate on a clock signal - it is a fully asynchronous dual-port SRAM. Its speed is defined by timing parameters: maximum read cycle time (tRC) is 55 ns, meaning it supports sustained access rates up to approximately 18.2 MHz in worst-case conditions. Actual throughput depends on address/control setup/hold times and system bus protocol.

Does the 7007S55J support 3.3 V operation?

No. The 7007S55J is specified exclusively for 5.0 V ±10% operation (4.5 V to 5.5 V). It is TTL-compatible and not rated for 3.3 V supply or I/O levels. Interfacing with 3.3 V processors requires level translation on all control, address, and data lines.

How does the BUSY arbitration logic function in master vs. slave configuration?

In master mode (M/S = HIGH), BUSYL and BUSYR are push-pull outputs that assert LOW when contention is detected on the opposite port. In slave mode (M/S = LOW), BUSYL and BUSYR become inputs - the external master drives them LOW to inhibit writes. This enables hierarchical arbitration in multi-device systems without additional logic.

Can the 7007S55J be used as a single-port SRAM?

Yes. Either port can be used independently by tying unused control signals (e.g., CER, OER, R/WR) to inactive states (HIGH for CE/OE, HIGH for R/W to disable writes). The unused port's I/O and address lines must be high-impedance or pulled to valid logic levels to avoid contention or excessive current draw.

What is the purpose of the SEM pin, and how is it used?

The SEM (Semaphore Enable) pin selects between RAM access mode (SEM = HIGH) and semaphore register mode (SEM = LOW). When SEM = LOW and CE = HIGH, the device decodes A0–A2 to select one of eight semaphore flags, allowing atomic read/write operations for resource locking - a critical feature for multi-CPU synchronization in the 7007S55J.