Renesas 71342SA25JI

Overview

IDT71342SA25JI from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with on-chip semaphore logic, operating at 25 ns max access time over –40°C to +85°C industrial temperature range, powered by single 5V ±10% supply, and used in real-time interprocessor communication systems requiring concurrent memory access without arbitration delay.

For engineers reviewing the IDT71342SA25JI datasheet, IDT71342SA25JI pinout, IDT71342SA25JI application, or IDT71342SA25JI equivalent, this device delivers deterministic port-to-port synchronization via hardware semaphores, supports battery-backed data retention (LA variant only), and enables lock-free resource sharing in embedded multiprocessor architectures.

Technical Context

The IDT71342SA25JI implements fully asynchronous dual-port operation: left and right ports feature independent address, control, and I/O buses, allowing simultaneous read/write to distinct memory locations. Its dedicated 3-bit address space (A0–A2) accesses eight semaphore latches, each active-low and write-locked per port upon zero-write.

Semaphore arbitration uses priority-resolving combinational logic that guarantees exclusive flag ownership-even during simultaneous write attempts-while full standby current drops to 0.2 mA (typ.) under CMOS-level CE/SEM high conditions. The device uses CMOS high-performance fabrication for 700 mW typical active power dissipation.

Key Specifications

Pinout & 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 CY7C1342BV25JC and AS7C34098B-25JIN, the IDT71342SA25JI uniquely integrates full semaphore arbitration, automatic power-down, and industrial temperature rating in a compact 52-pin PLCC-reducing BOM count, eliminating external sync logic, and guaranteeing deterministic interlock timing without software overhead.

Availability

IDT71342SA25JI is available at Aetrix Electronics and suitable for real-time motion control, redundant safety PLCs, avionics data concentrators, and dual-core DSP co-processing requiring stable component supply across extended production lifecycles.

Supply support for IDT71342SA25JI 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, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The IDT71342 product line targets multiprocessor systems requiring deterministic, hardware-accelerated memory sharing-specifically engineered to replace software-based semaphores with cycle-exact, contention-free interprocessor synchronization.

FAQ

What is the maximum guaranteed access time for IDT71342SA25JI?

IDT71342SA25JI has a maximum access time (tAA) of 25 ns across the full industrial temperature range (–40°C to +85°C) and supply voltage (4.5 V to 5.5 V). This value is production-tested and guaranteed per datasheet Table 9a, applying to both SRAM and semaphore address spaces when operated within specified DC and AC conditions.

Does IDT71342SA25JI support battery backup for data retention?

No, IDT71342SA25JI does not support battery backup data retention. That capability is exclusive to the LA variant (e.g., IDT71342LA25JI), which specifies 2.0 V minimum VCC for data retention and 100 µA typical ICCDR. The SA suffix denotes standard power grade without retention mode.

How many semaphore flags does IDT71342SA25JI provide, and how are they addressed?

IDT71342SA25JI provides eight independent semaphore flags, accessed exclusively via address lines A0–A2 (3 bits = 8 combinations) when SEM is asserted low. All other address lines (A3–A11) are ignored during semaphore access, and only I/O0 carries write data; reads return the flag state across all eight I/O lines.

What is the function of the SEM pin on IDT71342SA25JI?

The SEM pin on IDT71342SA25JI is an active-low semaphore select that toggles the internal memory map: when SEM = VIH, the device operates as a standard 4K × 8 dual-port RAM; when SEM = VIL, the same address/data/control signals access the eight semaphore latches instead of RAM cells-enabling hardware resource locking without external logic.

Can both ports of IDT71342SA25JI perform simultaneous writes to the same memory location?

No-simultaneous writes to the same non-semaphore memory location by both ports are undefined and must be avoided. The datasheet explicitly states conflict arises from "simultaneous writing of, or a simultaneous READ/WRITE of, a non-semaphore location." Hardware semaphores exist precisely to prevent such collisions via coordinated access control.