Renesas 70V261S35PF

Overview

70V261S35PF from IDT (Integrated Device Technology) is a high-speed, 3.3V, 16K × 16 true dual-port static RAM with independent left/right ports, 35 ns maximum access time, integrated semaphore and interrupt logic, and master/slave arbitration-designed for real-time inter-processor communication in telecom switching fabric and industrial motion control systems.

For engineers reviewing the 70V261S35PF datasheet, 70V261S35PF pinout, 70V261S35PF application, or 70V261S35PF equivalent, this device delivers deterministic port-to-port arbitration, hardware semaphore signaling across eight flags, and push-pull BUSY/INT outputs-critical for lock-free shared-memory designs requiring sub-40 ns latency and zero external logic.

Technical Context

The 70V261S35PF implements fully asynchronous dual-port operation with separate address, control, and I/O buses per port, enabling simultaneous read/write to any memory location without internal contention-except when both ports access identical addresses, triggering on-chip arbitration via push-pull BUSY outputs. Its semaphore logic uses A0–A2 to select one of eight dedicated flag locations, writable via I/O0 and readable across all 16 I/O lines.

Interrupt functionality is implemented through two mailbox addresses (3FFE_H for INTL, 3FFF_H for INTR), where write-to-flag asserts the opposite port's interrupt output; clearing requires a read (for INTR) or read-enable cycle (for INTL). The M/S pin configures BUSY as output (master) or input (slave), enabling scalable width expansion with single-master arbitration.

Key Specifications

Pinout & Package

70V261S35PF is housed in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, body size 14 mm × 14 mm × 1.4 mm. All VCC and GND pins must be connected per layout guidelines; N/C pins are internally unconnected and must remain floating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136-35JC and AS7C3256B-35JC, the 70V261S35PF uniquely integrates true dual-port access, hardware semaphore, and interrupt signaling in a 3.3 V, 16K × 16 package-enabling deterministic, low-jitter inter-processor communication without external glue logic or voltage translation.

Availability

70V261S35PF is available at Aetrix Electronics and suitable for telecom infrastructure, industrial motion control, and medical imaging systems requiring stable component supply, long-term lifecycle assurance, and guaranteed commercial-grade timing performance.

Supply support for 70V261S35PF 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

IDT (Integrated Device Technology) is a fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 70V261S35PF belongs to IDT's high-speed dual-port SRAM product line, engineered specifically for deterministic inter-processor communication in real-time embedded systems where latency, reliability, and hardware arbitration are critical.

FAQ

What is the maximum operating temperature range for the 70V261S35PF?

The 70V261S35PF is rated for commercial temperature operation from 0°C to +70°C. It is not qualified for industrial (-40°C to +85°C) use; that capability is reserved for the 70V261L variant. This makes the 70V261S35PF appropriate for controlled-environment applications such as office-based telecom equipment or laboratory instrumentation where ambient thermal stability is assured.

Does the 70V261S35PF support true simultaneous read/write to the same memory address?

No-the 70V261S35PF does not allow true simultaneous read/write to the same address. When both ports access identical locations, on-chip arbitration asserts BUSYL or BUSYR to stall the later access. This hardware-enforced serialization prevents data corruption and is fundamental to the device's deterministic behavior in real-time systems.

How many semaphore flags does the 70V261S35PF provide, and how are they accessed?

The 70V261S35PF provides eight dedicated binary semaphore flags, addressed by A0–A2. They are accessed by setting SEM = VIL and CE = VIH (opposite of normal RAM access), then writing to I/O0 (to set) or reading across I/O0–I/O15 (to read). This isolated access path ensures semaphore operations never interfere with main memory transactions.

Can the 70V261S35PF be used in a 32-bit data bus configuration?

Yes-the 70V261S35PF supports 32-bit expansion via its Master/Slave architecture. One device operates as master (M/S = VIH) to generate BUSY arbitration, while others act as slaves (M/S = VIL) using BUSY as a write-inhibit input. This configuration enables full-speed, error-free 32-bit word transfers without external logic.

What is the function of the M/S pin on the 70V261S35PF?

The M/S pin configures the 70V261S35PF as either master (M/S = VIH) or slave (M/S = VIL). In master mode, BUSYL and BUSYR are push-pull outputs indicating port contention; in slave mode, they become inputs that gate write operations. This pin enables scalable width expansion while maintaining deterministic arbitration across multiple devices.