Renesas 71342LA70JI

Overview

IDT71342LA70JI 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 cycle time, 5 V ±10% supply, and industrial temperature range (–40°C to +85°C). It supports fully asynchronous dual-port access, provides battery-backed data retention down to 2 V, and is used in real-time interprocessor communication systems requiring concurrent memory access without software arbitration.

For engineers reviewing the IDT71342LA70JI datasheet, IDT71342LA70JI pinout, IDT71342LA70JI application, or IDT71342LA70JI equivalent, key selection criteria include dual-port timing compatibility (tRC = 70 ns), 2 V data retention capability, PLCC-52 package footprint, TTL-compatible I/O levels, and hardware semaphore flag behavior for lock-free resource sharing between independent processors.

Technical Context

The IDT71342LA70JI implements two fully independent asynchronous ports-left (L) and right (R)-each with dedicated address (A0L–A11L / A0R–A11R), data (I/O0L–I/O7L / I/O0R–I/O7R), and control lines (CEL/CER, OEL/OER, R/WL/R/WR). Memory array size is exactly 4,096 × 8 bits, with eight additional semaphore flag locations mapped via A0–A2 under SEM = VIL.

Semaphore logic consists of eight independent latches accessible only when SEM = VIH (for SRAM) or SEM = VIL (for semaphore space), with active-low token semantics: writing '0' requests the flag, writing '1' releases it. The device uses CMOS technology, supports automatic power-down when CE and SEM are both HIGH, and guarantees no wait-state contention between ports during semaphore acquisition.

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 CY7C1352BV-70ZC and IDT71344LA70JG, the IDT71342LA70JI uniquely combines 52-pin PLCC mechanical robustness, guaranteed 2 V data retention, and industrial temperature qualification - making it optimal for field-deployed equipment where serviceability and power-fail resilience are mandatory.

Availability

IDT71342LA70JI is available at Aetrix Electronics and suitable for industrial motion control, avionics data acquisition, and medical imaging real-time FIFO applications requiring stable component supply across extended product lifecycles.

Supply support for IDT71342LA70JI 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 IDT71342LA product line delivers dual-port SRAMs with integrated semaphore logic specifically for deterministic interprocessor communication in real-time embedded systems where software arbitration introduces unacceptable latency.

FAQ

What is the maximum operating speed of the IDT71342LA70JI?

The IDT71342LA70JI has a maximum read cycle time (tRC) of 70 ns, corresponding to a theoretical maximum operating frequency of approximately 14.3 MHz for continuous sequential access. This timing is guaranteed across the full industrial temperature range (–40°C to +85°C) and 5 V ±10% supply, with no derating required. The IDT71342LA70JI achieves this performance using high-speed CMOS process technology while maintaining TTL-compatible voltage thresholds.

Does the IDT71342LA70JI support battery backup operation?

Yes, the IDT71342LA70JI supports battery backup operation with guaranteed data retention down to 2.0 V supply voltage (VDR), as specified in Table 7 of the datasheet. This feature is exclusive to the LA variant and enables nonvolatile state preservation during main power interruption. The typical data retention current (ICCDR) is 100 µA at 2 V, allowing multi-day retention from a standard CR2032 coin cell when combined with appropriate power-switching circuitry.

How are the semaphore flags accessed on the IDT71342LA70JI?

Semaphore flags on the IDT71342LA70JI are accessed by asserting SEM = VIL (low), which selects the 8-location semaphore address space. Only address lines A0–A2 are decoded for semaphore access; A3–A11 are ignored. Writing a '0' to I/O0L or I/O0R requests the flag; writing a '1' releases it. Reads return the flag state across all eight I/O lines (I/O0–I/O7), with '0' indicating token ownership and '1' indicating availability. The IDT71342LA70JI's semaphore logic ensures atomicity and prevents race conditions during simultaneous requests.

What package type is used for the IDT71342LA70JI?

The IDT71342LA70JI is packaged in a 52-pin Plastic Leaded Chip Carrier (PLCC), as confirmed by the pin configuration diagram on page 2 of the datasheet. This package features a square body measuring approximately 20.0 mm × 20.0 mm × 4.3 mm, with J-leads suitable for through-hole or surface-mount assembly. The PLCC-52 footprint provides mechanical stability and ease of rework compared to fine-pitch alternatives like TQFP, making it preferred in high-reliability industrial and aerospace applications.

Can both ports of the IDT71342LA70JI operate simultaneously?

Yes, both ports of the IDT71342LA70JI operate fully asynchronously and independently: reads and writes may occur concurrently on left and right ports to different memory locations without timing interference. However, simultaneous access to the same SRAM location (non-semaphore) creates undefined data outcomes and must be avoided via software or hardware arbitration. Semaphore locations are protected against such conflicts-the IDT71342LA70JI guarantees deterministic resolution when both ports attempt to acquire the same flag.