Renesas 71342SA55PFI

Overview

71342SA55PFI from IDT (Integrated Device Technology) is a high-speed 4K × 8 dual-port static RAM with integrated hardware semaphore logic, designed for real-time interprocessor communication in tightly coupled dual-CPU systems. It delivers 55 ns read cycle time, operates on single +5 V ±10% supply, supports industrial temperature range (–40°C to +85°C), and enables fully asynchronous, independent access from left and right ports - used in embedded control subsystems requiring deterministic memory arbitration.

For engineers reviewing the 71342SA55PFI datasheet, 71342SA55PFI pinout, 71342SA55PFI application, or 71342SA55PFI equivalent, key selection criteria include guaranteed 55 ns tRC timing, TTL-compatible I/O, dual-port power-down control via CE/SEM, and hardware semaphore flag contention resolution without software wait states.

Technical Context

The 71342SA55PFI implements two fully independent asynchronous SRAM ports sharing a 4K × 8 memory array and eight dedicated semaphore latches accessed via A0–A2 under SEM = VIL. Each port has separate address (A0L–A11L / A0R–A11R), data (I/O0L–I/O7L / I/O0R–I/O7R), and control lines (CEL/CER, OEL/OER, R/WL/R/WR).

Semaphore logic uses dual request latches per flag with priority arbitration: simultaneous write-0 requests resolve to exactly one side, and flag state is latched during read to prevent mid-cycle corruption. Power management includes four standby modes (ISB1–ISB4) controlled by CE/SEM voltage thresholds and input logic levels.

Key Specifications

Pinout & Package

71342SA55PFI is housed in a 64-pin TQFP (PNG64) package measuring 14 mm × 14 mm × 1.4 mm, with exposed thermal pad and standard 0.5 mm pitch. 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 with semaphore applications.

Compared with CY7C1371DV33-55AC and IDT71344SA55PFI, the 71342SA55PFI provides native hardware semaphore resolution in a compact TQFP package with zero external logic - reducing system latency, PCB area, and qualification risk in safety-critical dual-processor systems.

Availability

71342SA55PFI is available at Aetrix Electronics and suitable for industrial motion controllers, avionics data concentrators, and medical imaging subsystems requiring stable component supply across extended product lifecycles.

Supply support for 71342SA55PFI 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, specializes in high-performance timing, memory interface, and RF power solutions for communications, computing, and industrial markets.

The IDT71342 family was engineered specifically for deterministic dual-processor memory sharing in real-time embedded systems - prioritizing low-latency arbitration, industrial reliability, and seamless TTL-level integration.

FAQ

What is the maximum operating frequency supported by the 71342SA55PFI?

The 71342SA55PFI does not operate on a clock signal; it is an asynchronous SRAM. Its maximum effective throughput is governed by the 55 ns read cycle time (tRC), enabling up to ~18.2 MHz sustained random-access bandwidth per port. System-level frequency depends on controller timing margins and bus protocol overhead, not an internal clock.

Does the 71342SA55PFI support battery backup for data retention?

No, the 71342SA55PFI is the SA (standard power) variant and does not support battery backup. Only the LA variant (e.g., 71342LA55PFI) provides 2 V data retention capability. The SA version draws higher standby current and lacks the low-voltage retention circuitry specified in Table 7 of the datasheet.

How are the semaphore flags addressed and accessed on the 71342SA55PFI?

Semaphore flags reside in a separate 8-location address space accessed exclusively when SEM = VIL. Addressing uses only A0–A2 (3 bits → 8 flags); A3–A11 are ignored. Writes use only I/O0L or I/O0R; reads return the flag state across all 8 I/O lines. CE must be VIH during semaphore access.

Can both ports of the 71342SA55PFI perform simultaneous read operations without conflict?

Yes, the 71342SA55PFI supports true concurrent reads from both ports - no arbitration or timing penalty applies. Each port has independent address decoders and sense amplifiers, allowing full 55 ns access time on both sides simultaneously, provided non-semaphore memory locations are targeted.

What is the purpose of the ISB3 and ISB4 standby modes in the 71342SA55PFI?

ISB3 (full standby, both ports) and ISB4 (one-port standby) are ultra-low-power modes activated when CE and SEM inputs exceed VCC − 0.2 V. ISB3 draws just 1.0 mA typical and disables all internal circuitry; ISB4 allows one port to remain active while the other enters deep sleep - optimizing power in asymmetric workload scenarios.