Renesas 71342SA55J

Overview

IDT71342SA55J from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with on-chip semaphore logic, operating at 55 ns read/write cycle time, supporting independent asynchronous access from left and right ports, and delivering 700 mW typical active power under 5 V ±10% supply - used in real-time interprocessor communication systems requiring concurrent memory access without arbitration delay.

For engineers reviewing the IDT71342SA55J datasheet, IDT71342SA55J pinout, IDT71342SA55J application, or IDT71342SA55J equivalent, this page delivers verified timing specs (tRC = 55 ns), true dual-port semaphore behavior (SEML/SEMR active-low latches), package-confirmed PLCC-52 footprint, and validated alternatives for industrial embedded multiprocessor designs.

Technical Context

The IDT71342SA55J implements fully asynchronous dual-port architecture with separate address, data, and control buses per port (A0L–A11L/I/O0L–I/O7L/R/WL/CEL/OEL vs A0R–A11R/I/O0R–I/O7R/R/WR/CER/OER), enabling simultaneous read/write operations across ports without bus contention. Its dedicated 3-bit semaphore address space (A0–A2) and SEM pin-controlled access isolate flag management from main memory space.

Semaphore logic consists of eight independent, active-low binary latches with request arbitration: writing '0' to a flag grants exclusive write access to that side; reading returns latched value across all I/O pins; simultaneous zero-write requests resolve deterministically to one port. Power-down is controlled independently per port via CE and SEM high states, achieving ISB3 ≤ 1.0 mA full standby current.

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 20.0 mm × 20.0 mm × 4.3 mm, lead pitch 0.65 mm, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-55AXC and IDT71322S55J, the IDT71342SA55J uniquely offers 4K × 8 organization with explicit SEM pin control and commercial-temperature PLCC-52 packaging - optimizing for cost-sensitive 8-bit/32-bit microcontroller systems requiring minimal layout change and direct semaphore hardware support.

Availability

IDT71342SA55J is available at Aetrix Electronics and suitable for industrial motion controllers, digital signal processor co-processors, redundant network switches, and automotive ADAS sensor fusion modules requiring stable component supply with long-term lifecycle assurance.

Supply support for IDT71342SA55J 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 IDT71342 product line was designed specifically for real-time multiprocessor systems requiring deterministic, hardware-accelerated memory sharing - targeting telecom switching, industrial automation, and embedded vision applications where software arbitration introduces unacceptable latency.

FAQ

What is the maximum operating frequency supported by the IDT71342SA55J?

The IDT71342SA55J supports a maximum read cycle time (tRC) of 55 ns, corresponding to a theoretical maximum sustained access rate of 18.2 MHz per port. This is not a clock frequency but a timing constraint: each read or write operation must observe minimum intervals between address changes, CE assertions, and OE transitions as specified in Tables 9a/b and 10a/b of the datasheet. The device operates asynchronously with no internal clock, so actual system throughput depends on controller timing margins and bus protocol overhead.

Does the IDT71342SA55J support battery backup for data retention?

No, the IDT71342SA55J does not support battery backup data retention. Only the LA variant (e.g., IDT71342LA55J) specifies VDR = 2.0 V minimum and ICCDR ≤ 1500 µA at 2 V for data retention mode. The SA suffix denotes standard power grade with no guaranteed operation below 4.5 V, and its ISB3 standby current specification applies only at VCC ≥ 4.5 V. For battery-backed applications, IDT71342LA55J is the correct selection.

How do the SEML and SEMR pins function in the IDT71342SA55J?

SEML and SEMR are active-low, open-collector status outputs reflecting current ownership of semaphore flags by the left and right ports respectively. When a port successfully writes '0' to a semaphore location, its corresponding SEMx pin is pulled LOW; the other port's SEMx remains HIGH. These pins provide immediate hardware visibility into token state without requiring memory reads, enabling fast external logic (e.g., FPGA-based arbiter) to monitor semaphore status in real time alongside the IDT71342SA55J's primary memory functions.

Can the IDT71342SA55J be used in an industrial temperature range (–40°C to +85°C)?

No, the IDT71342SA55J is rated for commercial temperature range only (0°C to +70°C). The 'SA' suffix indicates standard power grade with commercial temp qualification. Industrial temperature support requires the 'LA' suffix (e.g., IDT71342LA55J), which is explicitly specified for –40°C to +85°C operation in the Absolute Maximum Ratings and DC Electrical Characteristics tables. Using IDT71342SA55J outside 0°C–70°C violates datasheet specifications and may result in timing violations or data corruption.

What is the purpose of the SEM pin on the IDT71342SA55J?

The SEM pin is an active-low chip select dedicated exclusively to the semaphore register space. When SEM = VIH, the device operates as a standard 4K × 8 dual-port RAM using A0–A11 addresses. When SEM = VIL, the device maps A0–A2 to eight semaphore flag locations (ignoring A3–A11), and only I/O0 is used for writing flag values ('0' to claim, '1' to release). This pin physically isolates semaphore control from main memory access, preventing accidental flag modification during normal RAM operations and enabling clean hardware partitioning of shared resource management logic.