Renesas 70V24S55PFI8

Overview

70V24S55PFI8 from IDT (Integrated Device Technology) 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 industrial temperature range (–40°C to +85°C). It integrates on-chip semaphore logic and BUSY/INT flags for inter-processor communication in real-time embedded systems.

For engineers reviewing the 70V24S55PFI8 datasheet, 70V24S55PFI8 pinout, 70V24S55PFI8 application, or 70V24S55PFI8 equivalent, key selection criteria include dual-port arbitration timing, 84-pin PLCC package compatibility, low-power standby current (660 µA typ.), and semaphore flag coherency under concurrent access.

Technical Context

The 70V24S55PFI8 implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port, enabling simultaneous read/write operations to the same memory location without external arbitration logic. Its on-chip hardware semaphore system uses A0–A2 addressing to manage eight shared resource flags across both ports.

It supports MASTER/SLAVE cascading via M/S pin to expand data bus width beyond 16 bits, with BUSY output (Master) or input (Slave) signaling and non-tri-stated push-pull INT/BUSY outputs. All I/Os are LVTTL-compatible and operate from a single 3.3 V ±0.3 V supply.

Key Specifications

Pinout & Package

70V24S55PFI8 is housed in an 84-pin Plastic Leaded Chip Carrier (PLCC, package code PLG84), with body dimensions approximately 1.15 in × 1.15 in × 0.17 in. All VDD pins require connection to 3.3 V supply; all VSS pins must be grounded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-55AXI and IDT70V25S55PF8, the 70V24S55PFI8 uniquely delivers industrial-temperature-rated dual-port operation in an 84-pin PLCC package with built-in BUSY/INT signaling and hardware semaphore support - eliminating external glue logic and simplifying thermal design.

Availability

70V24S55PFI8 is available at Aetrix Electronics and suitable for real-time inter-processor communication, digital signal processing buffering, and industrial PLC memory expansion requiring stable component supply and long-term industrial-grade availability.

Supply support for 70V24S55PFI8 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, is a fabless semiconductor company specializing in timing, memory interface, RF, and high-performance computing solutions.

The IDT70V24 product line delivers high-speed, low-power dual-port SRAMs optimized for deterministic inter-processor communication in industrial automation, aerospace, and telecom infrastructure.

FAQ

What is the maximum operating frequency supported by the 70V24S55PFI8?

The 70V24S55PFI8 has a 55 ns maximum read cycle time (tRC), supporting sustained operation up to 18.2 MHz. This value is measured under specified AC test conditions (VDD = 3.3 V, TA = +25°C, load per Figure 2), and actual system frequency depends on address/control setup/hold timing margins and PCB layout. The 70V24S55PFI8 does not include an internal clock generator - it operates asynchronously.

Does the 70V24S55PFI8 support true simultaneous read/write operations to the same memory address?

Yes, the 70V24S55PFI8 implements true dual-port SRAM cells that allow independent, asynchronous reads or writes from either port to the same memory location. When contention occurs, the on-chip arbitration logic asserts the BUSY flag on the requesting port, preventing data corruption. This behavior is confirmed in the Functional Block Diagram and Truth Table I of the official datasheet.

What is the function of the M/S pin on the 70V24S55PFI8, and how should it be configured?

The M/S (Master/Slave Select) pin configures arbitration behavior: VIH sets the 70V24S55PFI8 as Master (BUSY pin functions as output), while VIL configures it as Slave (BUSY pin functions as input). In multi-device systems, one device must be Master and others Slave to enable cascaded BUSY handshaking for wider data bus expansion. This configuration is required for proper semaphore and BUSY flag coordination.

Can the 70V24S55PFI8 be used in a single-port configuration?

Yes, the 70V24S55PFI8 can operate with only one port active - for example, by holding CEL = VIH (disabling left port) and using only right-port signals (CER, R/WR, OER, etc.). In this mode, it behaves as a standard high-speed 4K x 16 SRAM with full timing performance and low standby current. Unused port pins may be left unconnected or tied to appropriate logic levels per design requirements.

What are the voltage level requirements for the 70V24S55PFI8 control inputs?

The 70V24S55PFI8 requires LVTTL-compatible input levels: VIH ≥ 2.0 V (minimum) and VIL ≤ 0.8 V (maximum) over the full industrial temperature range. Input leakage current is guaranteed ≤10 µA (max) at VDD = 3.6 V. These thresholds ensure reliable interfacing with 3.3 V microcontrollers, FPGAs, and ASICs without level-shifting circuitry.