Renesas 70V261S35PF8

Overview

70V261S35PF8 from IDT is a high-speed 3.3V 16K × 16 true dual-port static RAM with independent left/right ports, 35 ns max access time (commercial grade), integrated semaphore logic, interrupt flag support, and master/slave arbitration for 32-bit+ bus expansion. It enables simultaneous read/write to the same memory location in real-time inter-processor communication systems.

For engineers reviewing the 70V261S35PF8 datasheet, 70V261S35PF8 pinout, 70V261S35PF8 application, or 70V261S35PF8 equivalent, key selection criteria include dual-port contention handling via BUSY arbitration, TTL-compatible 3.3V operation, on-chip semaphore addressing (A0–A2), interrupt mailbox locations (3FFE/3FFF), and TQFP-100 packaging with 14 mm × 14 mm footprint.

Technical Context

The 70V261S35PF8 implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port-no shared timing constraints between left and right sides. Its hardware arbitration uses chip enable (CEL/CER) and address match detection (A0L–A13L vs. A0R–A13R) to assert BUSYL/BUSYR within 35 ns, independent of R/W state.

Interrupt signaling operates via dedicated SRAM mailboxes: INTL asserts when CER/R/WR = VIL at address 3FFE_H; INTR asserts when CEL/R/WL = VIL at 3FFF_H. Semaphore access requires CE = VIH and SEM = VIL, enabling eight binary flags addressed by A0–A2 and written via I/O0 only.

Key Specifications

Pinout & Package

70V261S35PF8 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; package includes 32 I/O pins (16 per port), dual BUSY/INT/SEM/CE/OE/R/W controls, and M/S select for master/slave mode.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C026V-35AXC and AS7C316000B-35JCIN, the 70V261S35PF8 uniquely integrates hardware semaphore addressing, dual interrupt mailboxes, and configurable master/slave arbitration-reducing firmware complexity and PCB area in tightly coupled multi-processor systems requiring sub-35 ns contention resolution.

Availability

70V261S35PF8 is available at Aetrix Electronics and suitable for real-time inter-processor communication, digital signal processing buffering, and industrial PLC memory expansion requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for 70V261S35PF8 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 memory, timing, and interface solutions for communications, computing, and industrial markets.

The 70V261S35PF8 belongs to IDT's high-speed dual-port SRAM product line, designed specifically for deterministic, low-latency inter-processor communication in embedded control, DSP, and networking systems.

FAQ

What is the maximum operating speed of the 70V261S35PF8?

The 70V261S35PF8 has a maximum access time of 35 ns for commercial-grade operation, corresponding to a maximum read cycle time (tRC) of 35 ns. This enables sustained data throughput of up to 28.6 MB/s per port at 3.3 V supply, with timing validated across 0°C to +70°C ambient temperature.

How does the BUSY arbitration logic function in the 70V261S35PF8?

In master mode (M/S = VIH), the 70V261S35PF8 monitors address and chip enable signals on both ports; if A0L–A13L matches A0R–A13R while CEL and CER are both active, BUSYL and BUSYR assert within 35 ns to block conflicting writes. In slave mode (M/S = VIL), BUSY pins become write-inhibit inputs, allowing centralized arbitration by a master device.

Can the 70V261S35PF8 be used in industrial temperature environments?

No-the 70V261S35PF8 is rated for commercial temperature range only (0°C to +70°C). For industrial operation (–40°C to +85°C), the pin-compatible 70V261L35PF8 variant must be selected; it shares identical timing and feature set but specifies lower standby current (660 µW typ.) and extended thermal validation.

What are the interrupt mailbox addresses for the 70V261S35PF8?

The 70V261S35PF8 uses two dedicated SRAM locations as interrupt mailboxes: address 3FFE_H triggers the left-port interrupt flag (INTL) when written by the right port, and address 3FFF_H triggers the right-port interrupt flag (INTR) when written by the left port. These locations retain standard SRAM functionality when interrupts are unused.

How many semaphore flags does the 70V261S35PF8 support, and how are they accessed?

The 70V261S35PF8 provides eight binary semaphore flags, addressed by A0–A2. Access requires CE = VIH and SEM = VIL; writing is performed exclusively via I/O0, while reading returns the flag value on all 16 I/O lines (I/O0–I/O15), enabling atomic token-passing protocols between processors without additional bus cycles.