Renesas 70V25S35PF

Overview

70V25S35PF from Integrated Device Technology (IDT) is a high-speed 3.3V 4K x 16 true dual-port static RAM with independent left/right ports, 35 ns maximum read cycle time, 15 ns address access time, and industrial temperature support (–40°C to +85°C). It enables simultaneous asynchronous reads/writes to the same memory location in real-time communication systems requiring deterministic latency.

For engineers reviewing the 70V25S35PF datasheet, 70V25S35PF pinout, 70V25S35PF application, or 70V25S35PF equivalent, key selection criteria include dual-port arbitration logic, on-chip semaphore signaling for inter-processor synchronization, BUSY/INT flag support, and LVTTL-compatible 3.3V single-supply operation with low standby power (3.3 mW typical).

Technical Context

The 70V25S35PF implements fully asynchronous dual-port architecture with separate control, address, and I/O buses per port - enabling concurrent access without external arbitration logic. Its on-chip port arbitration resolves contention via hardware BUSY flag generation and supports master/slave cascading for 32-bit+ data bus expansion.

It integrates full semaphore logic with eight dedicated flags addressed by A0–A2, accessible via SEM pin control. Memory cells support true simultaneous read of identical locations, and byte-select (UBL/LBL, UBR/LBR) enables multiplexed bus compatibility with upper/lower byte isolation.

Key Specifications

Pinout & Package

70V25S35PF is housed in a 100-pin TQFP (PNG100) package, 14 mm × 14 mm × 1.4 mm body size, with 0.5 mm pitch and exposed thermal pad (not electrically connected). All VDD and VSS pins require proper decoupling per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C024AV-35AXC and AS7C34096B-35TIN, the 70V25S35PF uniquely delivers integrated BUSY arbitration and hardware semaphores in a 100-pin TQFP - reducing BOM count, eliminating layout risk from external logic, and guaranteeing sub-35 ns deterministic access for safety-critical real-time systems.

Availability

70V25S35PF is available at Aetrix Electronics and suitable for industrial PLCs, telecom line cards, avionics data loggers, and DSP co-processor interfaces requiring stable component supply across extended product lifecycles.

Supply support for 70V25S35PF 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, RF, and power management solutions for communications, computing, and industrial markets.

The IDT70V25 family was designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, semaphore support, and industrial-grade reliability over generic memory density.

FAQ

What is the maximum operating frequency supported by the 70V25S35PF?

The 70V25S35PF does not operate at a fixed clock frequency but supports asynchronous operation with a 35 ns maximum read cycle time (tRC), enabling effective throughput up to ~28.6 MHz in continuous read mode. Its timing is defined by access parameters (tAA, tACE, tAOE), not a system clock - making it suitable for event-driven architectures without synchronous clock distribution.

Does the 70V25S35PF support simultaneous read and write to the same memory address?

Yes, the 70V25S35PF features true dual-port SRAM cells that allow simultaneous reads from the same address on both ports. However, simultaneous write to the same address is not permitted - the on-chip arbitration logic asserts BUSY to prevent corruption, requiring software or hardware resolution before proceeding.

How is semaphore functionality implemented in the 70V25S35PF?

The 70V25S35PF implements eight hardware semaphore flags accessible via A0–A2 address lines and controlled by the SEM pin. When SEM = VIL and CE = VIH (or UB & LB = VIH), I/O0 writes to the selected flag and all I/O pins reflect its value on read - enabling atomic test-and-set operations without CPU intervention.

What is the role of the M/S pin on the 70V25S35PF?

The M/S (Master/Slave) pin configures BUSY behavior: when M/S = VIH, BUSY is an output flag indicating port contention; when M/S = VIL, BUSY becomes an input used to synchronize multiple devices in master/slave cascaded configurations - enabling 32-bit+ data bus expansion using IDT70V25/24 devices without external logic.

Can the 70V25S35PF operate with mixed voltage interfaces (e.g., 3.3V core, 1.8V I/O)?

No, the 70V25S35PF requires a single 3.3V ±0.3V supply for all I/O and core functions. Its inputs are LVTTL-compatible (VIH ≥ 2.0 V, VIL ≤ 0.8 V), and outputs swing rail-to-rail within the 3.3V domain. Level translation is required for interfacing with 1.8V or 2.5V logic families.