Renesas 7007S55JI8

Overview

7007S55JI8 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, industrial temperature range (–40°C to +85°C), and full on-chip semaphore and interrupt logic. It enables concurrent asynchronous access to shared memory in real-time inter-processor communication systems.

For engineers reviewing the 7007S55JI8 datasheet, 7007S55JI8 pinout, 7007S55JI8 application, or 7007S55JI8 equivalent, this device supports master/slave cascading for 16-bit+ data buses, features push-pull BUSY/INT outputs, TTL-compatible 5V ±10% operation, and integrated port arbitration-critical for deterministic multi-CPU designs.

Technical Context

The 7007S55JI8 implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port. Its on-chip arbitration logic resolves contention via BUSY flag assertion (M/S = H for master output; M/S = L for slave input), with tBDD ≤ 40 ns ensuring valid data after BUSY deassertion.

It supports two distinct memory access modes: standard RAM access (CE = VIL, SEM = VIH) and semaphore register access (CE = VIH, SEM = VIL), using A0–A2 to select among eight semaphore flags. Interrupts are triggered by writes to dedicated mailbox addresses (7FFE_H for INTL, 7FFF_H for INTR).

Key Specifications

Pinout & Package

7007S55JI8 is packaged in an 80-pin TQFP (Thin Quad Flat Package), body size 14 mm × 14 mm × 1.4 mm, lead pitch 0.5 mm. All VCC pins require decoupling; all GND pins must be connected to system ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1370D-55AC and AS7C33256B-55JC, the 7007S55JI8 uniquely delivers full hardware arbitration, semaphore, and interrupt functions in a 5 V TTL-compatible package-reducing design effort and component count for legacy or mixed-signal industrial systems.

Availability

7007S55JI8 is available at Aetrix Electronics and suitable for industrial PLC communication hubs, real-time motor control co-processors, and avionics sensor fusion modules requiring stable component supply and long-term lifecycle support.

Supply support for 7007S55JI8 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) is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal processing solutions, now part of Renesas Electronics.

The IDT7007 family was designed specifically for deterministic inter-processor communication in hard real-time systems-emphasizing hardware arbitration, low-latency access, and industrial reliability over density or power efficiency.

FAQ

What is the maximum operating frequency supported by the 7007S55JI8?

The 7007S55JI8 does not operate on a clock signal-it is fully asynchronous. Its maximum effective bandwidth is determined by the 55 ns read cycle time (tRC), enabling up to ~18.2 MHz sustained random access throughput per port under ideal timing conditions with proper address/control setup.

Does the 7007S55JI8 require external pull-up resistors on BUSY or INT pins?

No. The 7007S55JI8 features push-pull BUSY and INT outputs (BUSYL, BUSYR, INTL, INTR), eliminating the need for external pull-ups. These outputs drive actively high or low, providing clean, rail-to-rail signaling compatible with TTL inputs without additional components.

How does the M/S pin affect arbitration behavior in a multi-device 7007S55JI8 configuration?

When M/S = H, the 7007S55JI8 operates as a master: BUSYL and BUSYR become outputs that assert during contention. When M/S = L, it operates as a slave: BUSYL and BUSYR become inputs that accept BUSY signals from a master device, disabling local writes until BUSY goes high-enabling hierarchical arbitration in cascaded systems.

Can the 7007S55JI8 be used in a single-port configuration?

Yes. Either port (left or right) can be used independently by tying unused control signals (e.g., CER, R/WR, OER) to inactive states (V_CC). The 7007S55JI8 retains full functionality-including standby modes and interrupt/mailbox features-as a standalone 32K × 8 SRAM, with no penalty to timing or power.

What is the purpose of the semaphore function in the 7007S55JI8, and how is it accessed?

The semaphore function in the 7007S55JI8 provides eight hardware flags for resource locking between processors. It is accessed by setting CE = V_HH and SEM = V_IL, then using A0–A2 to select flag 0–7; I/O0 writes the flag state, and all I/O lines read its value-enabling atomic test-and-set operations without software intervention.