Renesas 71342LA55PF8

Overview

IDT71342LA55PF8 from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with integrated hardware semaphore logic, operating at 55 ns read/write cycle time, supporting independent asynchronous access from left and right ports, and enabling interprocessor resource arbitration in real-time embedded systems such as industrial motion controllers and telecom line cards.

For engineers reviewing the IDT71342LA55PF8 datasheet, IDT71342LA55PF8 pinout, IDT71342LA55PF8 application, or IDT71342LA55PF8 equivalent, key selection criteria include 55 ns access timing, 2V data retention capability, industrial temperature range (–40°C to +85°C), TTL-compatible 5V ±10% supply, and full on-chip semaphore flag arbitration across both ports.

Technical Context

The IDT71342LA55PF8 implements two fully independent asynchronous memory ports sharing a single 4K × 8 SRAM array, with separate address, data, and control lines per port (A0L–A11L/I/O0L–I/O7L/R/WL/CEL/OEL vs A0R–A11R/I/O0R–I/O7R/R/WR/CER/OER). Each port supports concurrent read/write operations without bus contention except at non-semaphore addresses.

Semaphore logic resides in a dedicated 3-bit address space (A0–A2 only) accessed via SEM pin activation; it comprises eight independent latches with active-low token signaling, automatic contention resolution on simultaneous requests, and write-lock behavior where a zero written by one port blocks writes from the opposite port until a one is written.

Key Specifications

Pinout & Package

Package: 64-pin Thin Quad Flat Package (TQFP), body size 14 mm × 14 mm × 1.4 mm, lead pitch 0.5 mm, RoHS-compliant, plastic encapsulation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1370D-55AXC and AS7C34098B-55PCN, the IDT71342LA55PF8 uniquely combines industrial temperature support, 2V battery retention, and integrated semaphore logic in a 5V TTL-compatible 8-bit dual-port SRAM-making it irreplaceable for safety-critical, power-fail-resilient embedded systems requiring hardware-enforced concurrency control.

Availability

IDT71342LA55PF8 is available at Aetrix Electronics and suitable for industrial motion controllers, telecom line cards, medical imaging subsystems, and avionics data recorders requiring stable component supply across extended product lifecycles.

Supply support for IDT71342LA55PF8 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 sensor signal conditioning ICs for high-performance computing and communications infrastructure.

The IDT71342LA55PF8 belongs to IDT's legacy dual-port SRAM product line, designed specifically for real-time multiprocessor systems requiring deterministic memory access, hardware arbitration, and robust data retention under brownout conditions.

FAQ

What is the maximum operating frequency supported by the IDT71342LA55PF8?

The IDT71342LA55PF8 does not operate at a fixed clock frequency but supports asynchronous operation with a 55 ns read cycle time (tRC), corresponding to a theoretical maximum throughput of approximately 18.2 MHz for consecutive reads. Its timing is governed by parameter limits-not a synchronous clock-so system bus speed depends on controller timing margins and board layout.

Does the IDT71342LA55PF8 require external pull-up resistors on its control pins?

No, the IDT71342LA55PF8 does not require external pull-ups on R/WL, R/WR, CEL, CER, OEL, OER, SEML, or SEMR. Its input thresholds (VIH = 2.2 V min, VIL = 0.8 V max) are TTL-compatible, and internal design assumes driven logic levels; floating inputs are undefined and must be actively controlled per Truth Table I.

How is semaphore arbitration resolved when both ports attempt to claim the same flag simultaneously?

When both ports assert SEM = VIH and write D0 = 0 to the same semaphore location at identical timing, the IDT71342LA55PF8's on-chip logic guarantees exactly one port receives the token-the assignment is deterministic based on internal propagation delay asymmetry, not arbitrary. This is validated in the "Critical Case of Semaphore Timing" section of the datasheet.

Can the IDT71342LA55PF8 retain data during complete power loss?

Yes-the IDT71342LA55PF8 supports true battery backup: when VCC drops below 2.0 V, it enters data retention mode drawing ≤1500 µA (max) from a 2V source, preserving all 4K × 8 memory contents and semaphore states indefinitely as long as VCC remains ≥2.0 V, per Table 7 specifications.

Is the IDT71342LA55PF8 pin-compatible with other members of the IDT71342 family?

The IDT71342LA55PF8 uses the 64-pin TQFP (PNG64) package, which differs from the 52-pin PLCC used by IDT71342LA55PF. It is not pin-compatible with PLCC variants; however, it shares identical signal naming, function mapping, and timing specifications with other PNG64-packaged versions like IDT71342SA55PF8, differing only in power consumption profile.