Renesas 71342LA70J8

Overview

IDT71342LA70J8 from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with on-chip semaphore logic, operating at 70 ns max read/write cycle time, supporting independent asynchronous access from left and right ports, and featuring 2 V data retention in battery backup mode - used in real-time interprocessor communication systems requiring concurrent memory access without arbitration delays.

For engineers reviewing the IDT71342LA70J8 datasheet, IDT71342LA70J8 pinout, IDT71342LA70J8 application, or IDT71342LA70J8 equivalent, this device delivers deterministic port-to-port timing (tDDD = 70 ns), TTL-compatible 5 V ±10% operation, industrial temperature range (–40°C to +85°C), and hardware semaphore flag arbitration for lock-free shared resource management in embedded multiprocessor designs.

Technical Context

The IDT71342LA70J8 implements fully asynchronous dual-port architecture with separate address, control, and I/O buses for left (L) and right (R) ports, enabling simultaneous read/write operations without bus contention. Its dedicated 3-bit address space (A0–A2) accesses eight independent semaphore latches, each active-low and write-locked per port upon zero-write.

Semaphore arbitration uses edge-triggered request latches feeding a priority-resolving logic block that guarantees single-token assignment even during simultaneous requests. Power management includes four standby modes (ISB1–ISB4), with full CMOS-level standby current as low as 4.0 µA (typ.) when both CE and SEM are high and inputs held at rail extremes.

Key Specifications

Pinout & Package

Package: 64-pin TQFP (PNG64), body size 14 mm × 14 mm × 1.4 mm, lead pitch 0.5 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-70AXC and IDT71322LA70J8, the IDT71342LA70J8 uniquely combines full 4K × 8 capacity, integrated hardware semaphore arbitration, and 2 V battery retention - making it optimal for industrial and avionics systems demanding both memory bandwidth and deterministic interprocessor synchronization.

Availability

IDT71342LA70J8 is available at Aetrix Electronics and suitable for industrial PLC communication modules, military avionics data bus bridges, and medical imaging frame buffers requiring stable component supply across extended product lifecycles.

Supply support for IDT71342LA70J8 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 communications.

IDT71342LA70J8 belongs to IDT's legacy dual-port SRAM product line, designed specifically for deterministic, low-latency interprocessor communication in real-time embedded systems where hardware semaphore arbitration eliminates software-induced jitter.

FAQ

What is the maximum operating frequency supported by IDT71342LA70J8?

IDT71342LA70J8 does not operate on a clock signal - it is fully asynchronous. Its performance is defined by timing parameters: maximum read cycle time (tRC) is 70 ns, corresponding to an effective maximum throughput of ~14.3 MHz per port under worst-case conditions. Actual system speed depends on address setup, enable timing, and bus loading, not a fixed clock frequency.

Does IDT71342LA70J8 support true simultaneous read/write between ports?

Yes, IDT71342LA70J8 supports true simultaneous read/write operations between left and right ports - provided they target different memory locations. Concurrent access to the same non-semaphore address causes undefined data, but semaphore locations are protected against conflict via dedicated arbitration logic that guarantees exclusive write access per flag.

How is battery backup implemented in IDT71342LA70J8?

IDT71342LA70J8 supports battery backup via its LA variant's 2.0 V minimum data retention voltage (VDR). When main VCC drops below ~2.2 V, the device enters data retention mode with ICCDR ≤1500 µA (max), preserving memory contents using an external 2 V battery connected to VCC. No external circuitry is required beyond proper decoupling and battery isolation diodes.

What is the function of the SEM pins on IDT71342LA70J8?

SEML and SEMR are active-low semaphore select inputs. When asserted (LOW), they enable access to the 8 semaphore flag registers using A0–A2 only - decoupling semaphore control from main memory addressing. Writing '0' to a flag grants exclusive token ownership to that port; writing '1' releases it. This hardware mechanism replaces software mutexes with deterministic, sub-ns arbitration.

Is IDT71342LA70J8 pin-compatible with other members of the IDT71342 family?

IDT71342LA70J8 in the 64-pin TQFP (PNG64) package shares identical pinout with IDT71342SA70J8 and IDT71342LA25J8 in the same package variant. However, it is not pin-compatible with the 52-pin PLCC version (PLG52), which has different pin assignments and lacks several N/C and I/O pins present in the TQFP layout.