Renesas 71V321SA35PF

Overview

71V321SA35PF from Renesas Electronics (formerly IDT) is a high-speed 3.3V 2K × 8 dual-port static RAM with on-chip interrupt logic and BUSY arbitration for interprocessor communication. It features 35 ns max access time, TTL-compatible I/O, 2.0 V data retention (L version), and operates across commercial temperature range (0°C to +70°C). Used in real-time embedded systems requiring concurrent memory access from two independent controllers.

For engineers reviewing the 71V321SA35PF datasheet, 71V321SA35PF pinout, 71V321SA35PF application, or 71V321SA35PF equivalent, key selection criteria include dual-port arbitration timing (tBDD ≤ 30 ns), interrupt flag behavior (INTL/INTR at addresses 7FEh/7FFh), low-power standby current (ISB3 = 1.0 mA typ.), and compatibility with 52-pin PLCC or 64-pin TQFP footprints.

Technical Context

The 71V321SA35PF implements fully asynchronous dual-port operation with separate address, control, and bidirectional I/O buses for left and right ports. Its on-chip arbitration logic uses address and chip-enable signals-not R/W state-to assert BUSYL/BUSYR outputs when both ports access the same memory location simultaneously.

Interrupt functionality is implemented via dedicated mailbox addresses: writing to 7FFh (right port) sets INTR; writing to 7FEh (left port) sets INTL. Clearing occurs via read access to the same address with OE and CE asserted. All interrupt and BUSY timing parameters-including tINS/tINR (≤25 ns) and tBAA/tBDA (≤20 ns)-are specified for 35 ns speed grade under commercial conditions.

Key Specifications

Pinout & Package

71V321SA35PF is packaged in a 64-pin Thin Quad Flatpack (TQFP, package code PNG64), measuring 10 mm × 10 mm × 1.4 mm. Pin 1 is located at bottom-left corner (marked by dot or bevel), with pins numbered counter-clockwise.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-35AXC and AS7C3256B-35JCIN, the 71V321SA35PF uniquely integrates hardware BUSY arbitration and dedicated interrupt flag outputs-reducing firmware complexity and eliminating race conditions in tightly coupled dual-CPU designs-while maintaining identical 35 ns timing and commercial temperature compliance.

Availability

71V321SA35PF is available at Aetrix Electronics and suitable for industrial PLC communication bridges, real-time signal processing subsystems, automotive ADAS sensor fusion hubs, and telecom line card packet buffers requiring stable component supply across extended production lifecycles.

Supply support for 71V321SA35PF 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

Renesas Electronics Corporation is a global semiconductor leader delivering microcontrollers, analog, power, and SoC solutions for automotive, industrial, infrastructure, and IoT applications.

The 71V321SA35PF belongs to Renesas' legacy dual-port SRAM product line-originally developed by IDT-designed specifically for deterministic interprocessor communication in real-time embedded systems where hardware arbitration and low-latency interrupts are critical.

FAQ

What is the exact memory capacity and organization of the 71V321SA35PF?

The 71V321SA35PF provides 2K × 8 bits (2048 words × 8-bit data width) of static RAM, equally accessible through independent left and right ports. Each port has its own 11-bit address bus (A0–A10), supporting full 2048-location addressing without multiplexing. This configuration is fixed and not configurable via pins or registers.

Does the 71V321SA35PF support battery backup operation, and what voltage is required?

Yes, the 71V321SA35PF supports battery backup data retention at VCC ≥ 2.0 V, with typical data retention current of 100 µA at 2 V. This capability is inherent to the "L" (low-power) variant designation in the part number and is verified across the commercial temperature range (0°C to +70°C).

How does the BUSY arbitration logic function in the 71V321SA35PF, and what timing parameters govern it?

The 71V321SA35PF asserts BUSYL or BUSYR when both ports attempt to access the same memory address simultaneously. Arbitration is based solely on address and chip-enable signals-not R/W state-with tBAA ≤ 20 ns and tBDD ≤ 30 ns for the 35 ns speed grade. The winning port proceeds; the losing port's write is internally gated.

What are the interrupt mailbox addresses for the 71V321SA35PF, and how are they cleared?

The left port interrupt (INTL) is set when the right port writes to address 7FEh; the right port interrupt (INTR) is set when the left port writes to 7FFh. Both are cleared by the respective port performing a read access to the same address with CEL/CER and OEL/OER asserted (i.e., CE = L, OE = L). No additional control signals are required.

Is the 71V321SA35PF pin-compatible with other speed grades or package variants in the same family?

Yes, all 71V321Sx and 71V321Lx variants-including 25 ns, 35 ns, and 55 ns speed grades-share identical pinouts across the same package type (e.g., 64-pin TQFP). The 71V321SA35PF (35 ns, TQFP) is mechanically and electrically interchangeable with 71V321SA25PF or 71V321SA55PF, provided timing margins in the target design accommodate the slower/faster grade.