Renesas 7005S55J8

Overview

7005S55J8 from IDT is a high-speed 8K × 8 dual-port static RAM with true independent left/right ports, 55 ns max read cycle time (tRC), TTL-compatible 5V ±10% supply, and integrated hardware semaphore/arbitration logic - used in real-time inter-processor communication systems requiring simultaneous access to shared memory without external logic.

For engineers reviewing the 7005S55J8 datasheet, 7005S55J8 pinout, 7005S55J8 application, or 7005S55J8 equivalent, this page delivers verified timing specs (tRC = 55 ns, tAA ≤ 55 ns), dual-port arbitration behavior (BUSY/M/S-controlled), semiconductor-grade standby current (ISB1 = 13 mA typ.), and exact TQFP-64 package mapping per official IDT documentation.

Technical Context

The 7005S55J8 implements fully asynchronous dual-port operation: each port (left/right) has dedicated address (A0L–A12L / A0R–A12R), data (I/O0L–I/O7L / I/O0R–I/O7R), and control lines (CEL/CER, R/WL/R/WR, OEL/OER). Port-to-port arbitration uses push-pull BUSY flags and Master/Slave select (M/S) to resolve contention at the hardware level.

It supports two distinct memory access modes: standard RAM access (CE = VIL, SEM = VIH) and semaphore register access (CE = VIH, SEM = VIL), with eight semaphore flags addressed via A0–A2. The device includes interrupt flag generation (INTL/INTR) triggered by write to specific addresses (e.g., 1FFFh for set, 1FFEh for reset).

Key Specifications

Pinout & Package

7005S55J8 is housed in a 64-pin TQFP (PNG64) package with 0.5 mm pitch, 14 mm × 14 mm footprint, and 1.4 mm height. Pin 1 marked via corner notch; all VCC pins require local decoupling, all GND pins must be connected to ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AXC and IDT70V25L25PF, the 7005S55J8 uniquely delivers 5V-only operation, industrial temperature rating, and hardware semaphore support in a compact 64-pin TQFP - making it optimal for cost-sensitive, mixed-voltage industrial controllers where pin count and voltage simplicity are critical.

Availability

7005S55J8 is available at Aetrix Electronics and suitable for real-time inter-processor communication, digital signal processing buffering, and redundant control system memory requiring stable component supply across extended product lifecycles.

Supply support for 7005S55J8 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, and RF solutions, now part of Renesas Electronics since 2019.

The IDT7005 family was designed specifically for high-reliability dual-ported memory applications in military, industrial, and telecommunications systems - emphasizing deterministic arbitration, low-latency access, and robust ESD tolerance (>2000 V).

FAQ

What is the maximum operating frequency supported by the 7005S55J8?

The 7005S55J8 does not operate at a fixed clock frequency; instead, its performance is defined by timing parameters. With a maximum read cycle time (tRC) of 55 ns, it supports effective memory access rates up to approximately 18.2 MHz in continuous sequential operation. Actual throughput depends on system-level timing margins, address/data setup/hold times, and bus protocol overhead - not a synchronous clock input.

Does the 7005S55J8 support battery backup for data retention?

No - the 7005S55J8 is the "S" (standard power) variant and does not include battery backup capability. Battery retention (down to 2 V) is exclusive to the "L" (low-power) versions such as IDT7005L55J8. The 7005S55J8 requires continuous 5V ±10% supply to maintain data integrity.

How does the M/S pin affect BUSY signal behavior on the 7005S55J8?

When M/S = HIGH, the 7005S55J8 operates as a master: BUSYL and BUSYR are push-pull outputs that assert LOW during port contention. When M/S = LOW, it operates as a slave: BUSYL and BUSYR become inputs, and external BUSY signals from a master device inhibit writes on the corresponding port - enabling hierarchical multi-device arbitration.

Can the 7005S55J8 be used in a 16-bit data bus configuration?

Yes - the 7005S55J8 supports 16-bit expansion via Master/Slave cascading. Two devices can be connected with M/S tied HIGH on one (master) and LOW on the other (slave); their I/O buses are combined to form a 16-bit interface while sharing address and control lines, eliminating need for external glue logic per the IDT7005 datasheet application note.

What is the purpose of the SEM pin on the 7005S55J8?

The SEM (semaphore enable) pin selects between RAM access mode (SEM = VIH) and semaphore register access mode (SEM = VIL). In semaphore mode, writes to I/O0 and reads from I/O0–I/O7 access eight hardware-managed flags addressed by A0–A2 - enabling atomic resource locking across processors without software intervention.