Renesas 7024S55JI

Overview

7024S55JI from IDT is a high-speed 4K × 16 true dual-port static RAM with independent left/right ports, 55 ns max read cycle time (tRC), TTL-compatible 5V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports simultaneous asynchronous access, on-chip semaphore arbitration, and battery backup data retention down to 2V - enabling use in real-time inter-processor communication buffers for avionics and industrial control systems.

For engineers reviewing the 7024S55JI datasheet, 7024S55JI pinout, 7024S55JI application, or 7024S55JI equivalent, key selection considerations include its dual-port arbitration logic, BUSY/INT flag signaling, byte-selectable I/O (UBL/LBL), and compatibility with master/slave cascading for 32-bit+ bus expansion without external glue logic.

Technical Context

The 7024S55JI implements fully asynchronous dual-port operation with separate address, control, and bidirectional I/O buses per port (A0L–A11L/I/O0L–I/O15L and A0R–A11R/I/O0R–I/O15R), enabling concurrent reads/writes to any memory location. Its on-chip arbitration logic resolves port contention via BUSY flag assertion and supports semaphore flag exchange using dedicated SEM pins and A0–A2 addressing.

It features hardware-supported semaphore signaling with eight flags accessible via I/O0–I/O15, and operates in three power states: active (750 mW typ.), standby (5 mW typ. for S version), and full standby (0.2 mA typ. under CMOS-level inputs). The device uses CMOS high-performance fabrication and retains data at VCC = 2V.

Key Specifications

Pinout & Package

7024S55JI is packaged in an 84-pin Plastic Leaded Chip Carrier (PLCC, package code PLG84), measuring approximately 1.15 in × 1.15 in × 0.17 in. All VCC and GND pins must be connected per datasheet note; unused pins (N/C) are internally unconnected.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C133-55JC and IDT70V24S55PF, the 7024S55JI uniquely delivers integrated semaphore logic, 2V data retention, and industrial temperature support in a single 5V-compatible package - making it irreplaceable in legacy-reliant, safety-critical, or battery-backed dual-port memory applications.

Availability

7024S55JI is available at Aetrix Electronics and suitable for industrial motion control, aerospace avionics, and programmable logic controller applications requiring stable component supply across extended product lifecycles.

Supply support for 7024S55JI 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 7024S55JI belongs to IDT's legacy high-speed dual-port SRAM family, designed specifically for deterministic inter-processor communication in real-time embedded systems where hardware arbitration and data retention are critical.

FAQ

What is the maximum operating speed of the 7024S55JI?

The 7024S55JI has a maximum read cycle time (tRC) of 55 ns, supporting effective memory bandwidth up to ~18.2 MHz in asynchronous operation. This value is guaranteed across the full industrial temperature range (–40°C to +85°C) and 5.0 V ±10% supply, making it suitable for deterministic real-time systems where worst-case timing must be assured.

Does the 7024S55JI support battery backup operation?

Yes, the 7024S55JI supports battery backup data retention down to VCC = 2.0 V, with typical data retention current of 100 µA (max 4000 µA) over the industrial temperature range. This feature enables nonvolatile state preservation during main power failure - critical for safety-critical controllers and avionics systems.

How does the Master/Slave (M/S) pin function in the 7024S55JI?

When M/S = H, the 7024S55JI operates as a master with BUSYR and BUSYL driven as outputs to signal port contention. When M/S = L, it operates as a slave with BUSYR and BUSYL configured as inputs for synchronization. This enables cascaded configurations where one device arbitrates while others respond - essential for expanding data bus width beyond 16 bits.

What is the purpose of the SEM pins on the 7024S55JI?

The SEML and SEMR pins enable access to the on-chip semaphore flag register - eight hardware flags addressed by A0–A2 and read/written via I/O0–I/O15. These flags provide atomic resource locking between ports without CPU involvement, eliminating race conditions in multi-threaded or multi-processor environments where shared memory access must be strictly serialized.

Which package type is used by the 7024S55JI?

The 7024S55JI is supplied in an 84-pin Plastic Leaded Chip Carrier (PLCC) package, designated PLG84 in IDT documentation. Its dimensions are approximately 1.15 in × 1.15 in × 0.17 in, with gull-wing leads compatible with standard surface-mount assembly processes and IPC-7351 footprint guidelines.