Renesas 7007S35JI

Overview

IDT7007S35JI from IDT (Integrated Device Technology) is a high-speed 32K × 8 dual-port static RAM with true independent left/right ports, 35 ns read cycle time, industrial temperature range (–40°C to +85°C), and 5 V ±10% single-supply operation. It enables simultaneous asynchronous access to shared memory in real-time inter-processor communication systems such as motor control co-processors and industrial PLC backplanes.

For engineers reviewing the 7007S35JI datasheet, 7007S35JI pinout, 7007S35JI application, or 7007S35JI equivalent, this page delivers verified timing specs, master/slave arbitration behavior, BUSY/INT signal timing, semaphore flag access protocol, and package-specific layout guidance for reliable dual-port memory integration.

Technical Context

The 7007S35JI implements fully asynchronous dual-port architecture with separate address, data, and control buses per port - no clock required. Its on-chip arbitration logic resolves contention via hardware BUSY flag assertion (push-pull, not open-drain) and supports both CE-controlled and address-match-based arbitration modes.

It integrates full semaphore signaling (8 flags, addressed by A0–A2) and interrupt generation via dedicated mailbox addresses (7FFE_H for INTL, 7FFF_H for INTR), with all control logic implemented in CMOS for deterministic latency and low power consumption.

Key Specifications

Pinout & Package

7007S35JI is packaged in an 80-pin TQFP (PNG80), body size 14 mm × 14 mm × 1.4 mm, with 4×20 pin grid, thermal pad exposed on underside. All VCC pins require local decoupling; all GND pins must be connected 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-35AXC and AS7C33256B-35JC, the 7007S35JI delivers native 5 V operation, integrated hardware arbitration, and on-chip semaphores - reducing system-level latency, PCB layer count, and firmware development effort for real-time inter-processor communication.

Availability

7007S35JI is available at Aetrix Electronics and suitable for industrial PLC backplanes, motor control co-processor interfaces, and avionics data concentrators requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 7007S35JI 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 ICs, now part of Renesas Electronics since 2019.

The IDT7007 family was designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, dual-port concurrency, and industrial-grade reliability over density or cost-per-bit.

FAQ

What is the maximum operating frequency supported by the 7007S35JI?

The 7007S35JI does not operate from a clock signal - it is a fully asynchronous static RAM. Its speed is defined by timing parameters: maximum read cycle time (tRC) is 35 ns, enabling effective throughput up to ~28.6 MHz in burst-read scenarios. Write cycle time (tWC) is also 35 ns, ensuring matched performance for read/write-intensive applications like real-time buffering.

How does the BUSY arbitration logic work in the 7007S35JI?

In the 7007S35JI, BUSY arbitration activates when both ports attempt access to the same memory address. If M/S = H (master), BUSYL/BUSYR become outputs asserting low to block the later-arriving write. If M/S = L (slave), BUSY pins serve as inputs accepting the master's BUSY signal. The tAPS setup time (5 ns) ensures deterministic priority resolution without software intervention.

Can the 7007S35JI be used in a master/slave configuration with more than two devices?

Yes - the 7007S35JI supports cascaded master/slave topologies using the M/S pin and BUSY signaling. One device is configured as master (M/S = H), others as slaves (M/S = L). The master's BUSY outputs connect to slaves' BUSY inputs, enabling hierarchical arbitration across multiple dual-port RAMs for wider data bus expansion (e.g., 16-bit or 32-bit systems) without external logic.

What are the valid interrupt mailbox addresses for the 7007S35JI?

The 7007S35JI uses fixed interrupt mailbox addresses: writing to address 7FFE_H (hex) via the right port asserts the left-port INTL flag; writing to 7FFF_H via the left port asserts the right-port INTR flag. Clearing is performed by reading those same addresses - e.g., reading 7FFF_H from the right port clears INTR. These locations remain standard SRAM cells when interrupts are unused.

Does the 7007S35JI support semaphore operations, and how are they accessed?

Yes - the 7007S35JI includes eight hardware semaphore flags. They are accessed by setting SEM = L (low) and CE = H (high), then using A0–A2 to select the flag (0–7), with I/O0 carrying the flag value. Writing I/O0 = L sets the flag; reading returns its state. This occurs independently of main RAM access, enabling lock-free synchronization between processors without memory contention.