Renesas 70V261L35PF

Overview

70V261L35PF 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, 660 µW standby power, and integrated semaphore/interrupt arbitration logic - used in real-time inter-processor communication systems requiring deterministic memory coherency.

For engineers reviewing the 70V261L35PF datasheet, 70V261L35PF pinout, 70V261L35PF application, or 70V261L35PF equivalent, this device delivers simultaneous asynchronous read/write access to shared memory with hardware-enforced conflict resolution via BUSY flag, semaphore flags, and interrupt signaling - critical for telecom control planes, industrial motion controllers, and FPGA-to-ASIC bridging architectures.

Technical Context

The 70V261L35PF implements fully asynchronous dual-port operation with separate address, control, and I/O buses per port (A0L–A13L/I/O0L–I/O15L and A0R–A13R/I/O0R–I/O15R), enabling concurrent access without clock synchronization. Its on-chip arbitration logic resolves port contention using address- and CE-based BUSY assertion, with push-pull BUSY outputs in master mode (M/S = VIH) and BUSY inputs in slave mode (M/S = VIL).

It integrates eight dedicated semaphore registers (addressed by A0–A2), accessible via SEM = VIL and CE = VIH, supporting binary token passing between processors. Interrupt flags (INTL/INTR) are triggered by writes to fixed mailbox addresses (3FFEh/3FFFh), with programmable clear behavior - all operating under single 3.3V ±0.3V supply with TTL-compatible I/O levels.

Key Specifications

Pinout & Package

70V261L35PF is housed in a 100-pin Thin Quad Flatpack (TQFP) with 0.5 mm pitch, body dimensions 14 mm × 14 mm × 1.4 mm, and exposed thermal pad (not electrically connected). All VCC and GND pins must be individually decoupled per manufacturer guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-133AXC and AS7C316098B-15JIN, the 70V261L35PF uniquely integrates arbitration, semaphore, and interrupt hardware - reducing BOM count and firmware latency at the expense of slightly longer access time and higher unit cost.

Availability

70V261L35PF is available at Aetrix Electronics and suitable for telecom line card control, industrial motion controller, FPGA-to-microcontroller bridge, and avionics data concentrator applications requiring stable component supply, long-term lifecycle support, and guaranteed commercial-grade timing compliance.

Supply support for 70V261L35PF 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, now part of Renesas Electronics since 2019.

The 70V261L35PF belongs to IDT's legacy high-speed dual-port SRAM product line, designed specifically for deterministic inter-processor communication in real-time embedded systems where hardware-enforced memory coherency is mandatory.

FAQ

What is the maximum access time specification for the 70V261L35PF?

The 70V261L35PF has a maximum access time of 35 ns under commercial temperature conditions (0°C to +70°C) and 3.3 V ±0.3 V supply. This applies to address access time (tAA), chip enable access time (tACE), and byte enable access time (tABE), ensuring deterministic timing for real-time inter-processor communication. The 70V261L35PF achieves this while maintaining only 660 µW standby power consumption.

How does the BUSY arbitration logic function in the 70V261L35PF?

The 70V261L35PF implements hardware BUSY arbitration based on simultaneous address and chip enable (CE) matching between ports. When both ports assert valid CE and identical addresses, the BUSY flag asserts within 35 ns (tBAA) to stall the later-arriving write. In master mode (M/S = VIH), BUSYL/BUSYR are push-pull outputs; in slave mode (M/S = VIL), they become write-inhibit inputs - enabling scalable width expansion without external logic.

Can the 70V261L35PF operate with only one port active?

Yes, the 70V261L35PF supports single-port operation with full functionality. When one port's CE is held high (e.g., CEL = VIH), that port enters ultra-low-power standby (660 µW typical), while the other port operates at full speed. The device retains all features - including interrupt mailbox access and semaphore operations - on the enabled port, making it suitable for asymmetric processing architectures.

What are the voltage thresholds for TTL-compatible operation of the 70V261L35PF?

The 70V261L35PF maintains TTL-compatible input thresholds: VIH ≥ 2.2 V and VIL ≤ 0.8 V, with VOH ≥ 2.4 V (at IOH = −4 mA) and VOL ≤ 0.4 V (at IOL = +4 mA). These levels ensure interoperability with legacy 3.3 V logic families without level shifters, while operating from a single 3.3 V ±0.3 V supply - verified across the full commercial temperature range.

How are the interrupt mailboxes configured in the 70V261L35PF?

The 70V261L35PF uses fixed-address interrupt mailboxes: INTL is asserted when the right port writes to address 3FFFh (HEX), and INTR is asserted when the left port writes to 3FFEh (HEX). Clearing is performed by reading the same address with OE and CE active. Both locations remain fully functional as general-purpose SRAM if interrupts are unused - no configuration register or initialization sequence is required for basic operation.