Renesas 7007S55JI

Overview

IDT7007S55JI from IDT (now Renesas) is a high-speed 32K × 8 dual-port static RAM with true independent left/right ports, 55 ns read cycle time, TTL-compatible 5 V ±10% operation, and integrated hardware semaphore/arbiter logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 7007S55JI datasheet, 7007S55JI pinout, 7007S55JI application, or 7007S55JI equivalent, this page delivers verified timing specs (tRC = 55 ns), industrial temperature support (–40°C to +85°C), dual-port arbitration behavior, and package-specific pin validation for reliable system integration.

Technical Context

The 7007S55JI implements fully asynchronous dual-port access with separate address, control, and I/O buses per port - enabling simultaneous reads from the same memory location without contention. Its on-chip arbitration logic uses BUSY flag signaling and Master/Slave (M/S) configuration to resolve port conflicts during concurrent writes.

It supports two distinct memory access modes: standard RAM access (CE = LOW, SEM = HIGH) and semaphore register access (CE = HIGH, SEM = LOW), with dedicated interrupt flags (INTL/INTR) tied to fixed addresses (7FFEh/7FFFh) and push-pull BUSY outputs compliant with TTL drive levels.

Key Specifications

Pinout & Package

7007S55JI is packaged in an 80-pin TQFP (Thin Quad Flat Package), measuring approximately 14 mm × 14 mm × 1.4 mm, with exposed thermal pad and lead-free RoHS-compliant finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AC and 70V27L25PF8, the 7007S55JI uniquely combines industrial temperature rating, 5 V TTL compatibility, integrated M/S arbitration, and fixed-address interrupt mailboxes - making it irreplaceable in legacy 5 V real-time control systems requiring drop-in dual-port SRAM functionality.

Availability

7007S55JI is available at Aetrix Electronics and suitable for real-time industrial PLCs, avionics data concentrators, and redundant flight control systems requiring stable component supply across extended product lifecycles.

Supply support for 7007S55JI 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), now part of Renesas Electronics, is a semiconductor leader specializing in high-performance memory, timing, and interface solutions for communications, computing, and industrial markets.

The IDT7007 family was designed specifically for deterministic inter-processor communication in hard real-time embedded systems, emphasizing hardware arbitration, low-latency dual-port access, and robust industrial temperature operation.

FAQ

What is the maximum operating temperature range for the 7007S55JI?

The 7007S55JI is rated for industrial temperature operation from –40°C to +85°C, validated per manufacturer specifications and tested across voltage (5.0 V ±10%) and timing (tRC = 55 ns) limits. This makes it suitable for deployment in harsh environments such as factory automation controllers and outdoor telecom equipment where ambient thermal stability cannot be guaranteed.

Does the 7007S55JI support true simultaneous reads from both ports to the same memory location?

Yes, the 7007S55JI implements true dual-ported memory cells that allow concurrent reads from identical addresses on the left and right ports without contention or timing penalty. This capability is intrinsic to its SRAM cell design and does not require external logic or arbitration - a key differentiator from pseudo-dual-port or FIFO-based alternatives.

How does the M/S pin affect BUSY signal behavior in the 7007S55JI?

When M/S = HIGH, the 7007S55JI operates as a MASTER: BUSYL and BUSYR are push-pull outputs reflecting port arbitration status. When M/S = LOW, it operates as a SLAVE: BUSYL and BUSYR become inputs that externally inhibit writes - enabling hierarchical multi-device configurations without additional glue logic.

Can the 7007S55JI be used in a 16-bit data bus configuration?

Yes, the 7007S55JI supports 16-bit expansion via MASTER/SLAVE cascading using the M/S pin. Two devices can be configured - one as MASTER (M/S = HIGH), one as SLAVE (M/S = LOW) - with their I/O ports combined to form a 16-bit wide interface while maintaining full-speed, error-free operation and shared semaphore/interrupt resources.

What are the valid interrupt address locations for the 7007S55JI and how are they triggered?

The 7007S55JI uses fixed addresses 7FFEh (for INTL) and 7FFFh (for INTR) as interrupt mailboxes. INTL asserts when the right port writes to 7FFEh (CER = R/WR = LOW); INTR asserts when the left port writes to 7FFFh (CEL = R/WL = LOW). Clearing is performed by reading the same address with OE enabled - all behavior is hardware-implemented and requires no firmware intervention.