Renesas 71342LA45JI

Overview

IDT71342LA45JI from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with on-chip semaphore logic, operating at 45 ns max read cycle time, 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports fully asynchronous dual-port access with independent left/right control, address, and I/O buses, and enables interprocessor resource arbitration in real-time embedded systems such as motor control co-processors and industrial PLCs.

For engineers reviewing the IDT71342LA45JI datasheet, IDT71342LA45JI pinout, IDT71342LA45JI application, or IDT71342LA45JI equivalent, key selection criteria include its 45 ns access timing, 2 V data retention capability (LA variant), 52-pin PLCC package, TTL-compatible I/O, and hardware semaphore flag arbitration for conflict-free shared memory access.

Technical Context

The IDT71342LA45JI implements two fully independent asynchronous SRAM ports sharing a single 4K × 8 memory array, with dedicated 3-bit address space (A0–A2) for eight binary semaphore latches. Semaphore access requires SEM = VIL and CE = VIH, while SRAM access requires SEM = VIH and CE = VIL - enabling strict functional separation between data storage and inter-processor coordination logic.

Each port features separate R/W, CE, OE, and address lines, allowing simultaneous read/write operations unless targeting the same non-semaphore memory location. The device uses CMOS technology with automatic power-down: ISB3 standby current is 1.0 µA (typ.) per port when CE and SEM are held above VCC – 0.2 V and inputs are at CMOS levels.

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 0.635 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 CY7C1342BV33-45AXI and IDT71322LA45JI, the IDT71342LA45JI uniquely combines 4K × 8 density, 5 V TTL compatibility, and 2 V battery retention - making it irreplaceable in industrial retrofits requiring legacy voltage support and nonvolatile operation.

Availability

IDT71342LA45JI is available at Aetrix Electronics and suitable for industrial PLCs, motor drive co-processors, avionics data buffers, and medical imaging frame stores requiring stable component supply across extended product lifecycles.

Supply support for IDT71342LA45JI 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, and RF power solutions for high-performance computing and industrial systems.

The IDT71342 family was designed specifically for deterministic interprocessor communication in real-time embedded systems - delivering hardware-accelerated semaphore arbitration alongside fast dual-port SRAM to eliminate software bottlenecks in multi-CPU architectures.

FAQ

What is the maximum access speed of the IDT71342LA45JI?

The IDT71342LA45JI has a guaranteed maximum read cycle time (tRC) of 45 ns and address access time (tAA) of 45 ns under industrial conditions (–40°C to +85°C, VCC = 5.0 V ±10%). This enables direct interfacing with 22 MHz microcontrollers and DSPs without wait states. The IDT71342LA45JI achieves this performance using high-speed CMOS process technology and optimized on-die decoding.

Does the IDT71342LA45JI support battery backup operation?

Yes, the IDT71342LA45JI supports battery backup with data retention down to 2.0 V (VDR), drawing ≤1500 µA typical current at +25°C. This feature is exclusive to LA variants and is validated per Table 7 in the datasheet. The IDT71342LA45JI retains full memory contents during main power loss, enabling safe shutdown and rapid restart in industrial control systems.

How are semaphore flags accessed on the IDT71342LA45JI?

Semaphore flags are accessed by asserting SEM = VIL and CE = VIH, then using A0–A2 to select one of eight flags; only I/O0 is used for writing, and all I/O pins reflect the flag state on read. The IDT71342LA45JI's semaphore logic ensures atomic claim/release behavior - a write of '0' requests the token, and a write of '1' releases it, with automatic contention resolution.

What package type is used for the IDT71342LA45JI?

The IDT71342LA45JI is packaged in a 52-pin Plastic Leaded Chip Carrier (PLCC), designated PLG52. Its footprint measures approximately 20.0 mm × 20.0 mm × 4.3 mm with 0.635 mm lead pitch. This package supports reflow soldering and is compatible with standard PLCC sockets for prototyping and field repair - confirmed in Figure 2 of the datasheet.

Can both ports of the IDT71342LA45JI operate simultaneously?

Yes, the IDT71342LA45JI supports true simultaneous access: one port can read while the other writes, or both can read, provided they target different memory locations. Concurrent writes to the same non-semaphore address cause undefined data, but semaphore flags are protected against such conflicts. The IDT71342LA45JI's fully asynchronous design ensures no timing interdependence between left and right port operations.