Renesas 71342SA20PF8

Overview

IDT71342SA20PF8 from Integrated Device Technology is a high-speed 4K × 8 dual-port static RAM with on-chip semaphore logic, operating at 20 ns (max) access time, TTL-compatible with single +5 V ±10% supply, and rated for commercial temperature range (0°C to +70°C). It supports fully asynchronous, independent read/write access from left and right ports and enables interprocessor resource arbitration in real-time embedded systems.

For engineers reviewing the IDT71342SA20PF8 datasheet, IDT71342SA20PF8 pinout, IDT71342SA20PF8 application, or IDT71342SA20PF8 equivalent, this device serves as a deterministic, hardware-accelerated memory coherency solution for multi-CPU architectures requiring zero-wait-state shared memory access and atomic semaphore flag control without software overhead.

Technical Context

The IDT71342SA20PF8 integrates two independent 4K × 8 SRAM arrays with separate address, data, and control buses (A0L–A11L/I/O0L–I/O7L/R/WL/CEL/OEL and A0R–A11R/I/O0R–I/O7R/R/WR/CER/OER), enabling concurrent port operations. Its dedicated 3-bit address space (A0–A2) selects among eight semaphore latches accessed via SEM = LOW, while CE and SEM jointly control per-port power-down modes.

Each semaphore flag is active-low, write-locked per side upon zero-write, and read-broadcast across all 8 I/O lines. The device uses CMOS high-performance fabrication, supports battery backup data retention only in LA variants (not applicable to SA grade), and requires no external arbitration logic - all contention resolution occurs within the on-die semaphore logic block.

Key Specifications

Pinout & Package

52-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 20.0 mm × 20.0 mm × 4.3 mm, lead pitch 0.65 mm. All VCC pins must be decoupled locally; all GND pins require low-inductance ground plane connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT71342SA20PF8, CY7C1342BV25AC trades speed for ruggedness and package modernity, while IDT71342LA25PF8 adds battery backup at the cost of access time and standby power behavior - neither is pin-compatible nor functionally identical, but both serve overlapping dual-CPU coherency roles.

Availability

IDT71342SA20PF8 is available at Aetrix Electronics and suitable for industrial motion controllers, dual-CPU test equipment, legacy bus bridge interfaces, and real-time communication gateways requiring stable component supply and long-term obsolescence management.

Supply support for IDT71342SA20PF8 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 infrastructure.

IDT71342SA20PF8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time embedded systems where software-based locking introduces unacceptable latency.

FAQ

What is the maximum guaranteed access time for IDT71342SA20PF8?

IDT71342SA20PF8 has a maximum guaranteed address access time (tAA) of 20 ns across the commercial temperature range (0°C to +70°C) and supply voltage of +5.0 V ±10%. This value is production-tested and applies to both left and right ports under worst-case conditions specified in the datasheet's AC Electrical Characteristics table.

Does IDT71342SA20PF8 support battery backup data retention?

No, IDT71342SA20PF8 does not support battery backup data retention. That feature is exclusive to the LA variant (e.g., IDT71342LA25PF8), which specifies 2 V minimum VCC for data retention. The SA grade is optimized for speed and commercial-temperature operation, with no characterization or guarantee for sub-4.5 V operation.

How are the semaphore flags addressed in IDT71342SA20PF8?

In IDT71342SA20PF8, the eight semaphore flags are accessed using only address pins A0–A2 while SEM = LOW and CE = VIH. Pins A3–A11 are ignored during semaphore access. Each flag corresponds to one of the eight combinations of A0–A2, and only I/O0 is used for writing; reads return the flag state across all eight I/O lines.

Can both ports of IDT71342SA20PF8 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 IDT71342SA20PF8 datasheet explicitly states that such conflicts may result in unpredictable data. Semaphore flags are protected against this, but general RAM locations require external coordination via the semaphore logic or software protocols.

What is the purpose of the SEM pin in IDT71342SA20PF8?

The SEM pin in IDT71342SA20PF8 is a low-active select signal that switches the device between RAM mode (SEM = HIGH) and semaphore mode (SEM = LOW). In semaphore mode, CE remains high, A0–A2 select one of eight flags, and I/O0 controls flag state - enabling atomic interprocessor signaling without accessing main memory space.