Renesas 70V24S55PF

Overview

70V24S55PF from Integrated Device Technology (IDT) is a high-speed 4K x 16 true dual-port static RAM with independent left/right asynchronous ports, 55 ns maximum read cycle time, 3.3 V single-supply operation, and integrated on-chip semaphore logic for inter-processor communication in real-time embedded systems.

For engineers reviewing the 70V24S55PF datasheet, 70V24S55PF pinout, 70V24S55PF application, or 70V24S55PF equivalent, this device serves as a drop-in memory solution for legacy IDT dual-port SRAM designs requiring industrial-grade timing, bus arbitration, and master/slave cascading in telecom line cards, motor control DSP interfaces, and FPGA co-processor buffers.

Technical Context

The 70V24S55PF implements fully asynchronous dual-port architecture with separate address, data, and control buses per port, enabling simultaneous read/write access to the same memory location without contention. It supports hardware-based port arbitration and full semaphore flag management across eight dedicated flags addressed via A0–A2.

It operates exclusively at 3.3 V ±0.3 V, uses CMOS high-performance fabrication, and features TTL-compatible I/O with push-pull BUSY/INT outputs. The device supports master/slave configuration via M/S pin for 32-bit+ bus expansion and includes automatic power-down via CE-controlled standby modes.

Key Specifications

Pinout & Package

70V24S55PF is housed in an 84-pin Plastic Leaded Chip Carrier (PLCC, package code PLG84), measuring approximately 1.15 in × 1.15 in × 0.17 in, with gull-wing leads suitable for wave soldering and rework-friendly socketing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-55AXC and IDT70V24L15PF, the 70V24S55PF offers legacy PLCC compatibility and proven integration in commercial-temperature telecom and industrial control systems, balancing timing margin, package familiarity, and supply chain stability.

Availability

70V24S55PF is available at Aetrix Electronics and suitable for telecom infrastructure, motor control systems, and FPGA co-processor buffering requiring stable component supply and long-term obsolescence management.

Supply support for 70V24S55PF 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

Integrated Device Technology (IDT), now part of Renesas Electronics, specialized in high-performance timing, memory, and interface ICs for communications, computing, and industrial markets.

The IDT70V24 family was designed specifically for real-time dual-processor systems requiring deterministic, contention-free memory sharing - targeting telecom line cards, motion controllers, and DSP-FPGA hybrid architectures.

FAQ

What is the maximum operating frequency supported by the 70V24S55PF?

The 70V24S55PF does not operate at a fixed clock frequency but supports asynchronous operation with a maximum read cycle time of 55 ns. This corresponds to a theoretical maximum sustained throughput of approximately 18.2 MHz for consecutive accesses. Actual system-level bandwidth depends on address/control setup/hold timing and bus turnaround overhead, not a synchronous clock input.

Does the 70V24S55PF support industrial temperature range operation?

No, the 70V24S55PF is specified only for commercial temperature range (0°C to +70°C). For industrial operation (−40°C to +85°C), IDT offered the 70V24L15PF variant - which has faster 15 ns timing and lower standby current but shares the same 84-pin PLCC package and pinout.

Can the 70V24S55PF be used in a master/slave configuration with other dual-port SRAMs?

Yes, the 70V24S55PF supports master/slave cascading via its M/S pin: when tied high, it acts as master and drives BUSYR; when tied low, it acts as slave and accepts BUSYL as input. This enables seamless expansion to 32-bit or wider data paths using multiple 70V24S55PF or compatible IDT70V25/24 devices without external logic.

What is the function of the A12 pin on the 70V24S55PF?

A12 is a no-connect (NC) pin on the 70V24S55PF, as confirmed in the official datasheet notes. It must remain unconnected on PCB layout - neither tied high, low, nor routed - to prevent unintended coupling or ESD paths that could disrupt adjacent signal integrity.

How does semaphore functionality work on the 70V24S55PF?

The 70V24S55PF provides eight hardware semaphore flags accessed via I/O0 (write) and all I/O lines (read), addressed by A0–A2. Semaphore mode is enabled when SEM = VIL and CE = VIH or UB/LB = VIH. Each flag supports atomic test-and-set operations, enabling lock-free synchronization between left and right ports without CPU intervention.