Renesas 70261L55PFI

Overview

70261L55PFI from IDT is a high-speed 16K × 16 true dual-port static RAM with interrupt and semaphore logic, operating at 55 ns max access time, supporting independent asynchronous read/write on left and right ports, and featuring 1 mW typical standby power for industrial applications including real-time inter-processor communication and video frame buffering.

For engineers reviewing the 70261L55PFI datasheet, 70261L55PFI pinout, 70261L55PFI application, or 70261L55PFI equivalent, key selection considerations include its 100-pin TQFP package, 5 V ±10% single-supply operation, industrial temperature range (−40°C to +85°C), and hardware-supported port arbitration via BUSY/INT/SEM signals.

Technical Context

The 70261L55PFI implements fully asynchronous dual-port architecture with separate address, control, and I/O buses per port, enabling simultaneous access to any memory location without external arbitration logic. Its on-chip arbitration uses push-pull BUSY flags and master/slave select (M/S) to coordinate contention resolution between ports.

It integrates dedicated interrupt flag registers at addresses 3FFE_H (left port) and 3FFF_H (right port), plus eight semaphore flags accessed via A0–A2 with CE = VIH and SEM = VIL. All timing parameters-including tAA = 55 ns, tRC = 55 ns, and tPD = 50 ns-are specified over the full industrial temperature range.

Key Specifications

Pinout & Package

70261L55PFI is housed in a 100-pin Thin Quad Flatpack (TQFP) measuring 14 mm × 14 mm × 1.4 mm, with 25 pins per side and exposed thermal pad (not electrically connected). All VCC and GND pins must be individually decoupled per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-55AXC and AS7C316000B-55JCIN, the 70261L55PFI delivers integrated hardware arbitration, interrupt mailboxes, and semaphore support-reducing BOM count, PCB area, and firmware complexity in tightly coupled multi-processor systems.

Availability

70261L55PFI is available at Aetrix Electronics and suitable for industrial motion control, avionics data acquisition, real-time inter-processor communication, and video frame buffering requiring stable component supply across extended temperature ranges.

Supply support for 70261L55PFI 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 timing, memory interface, RF, and high-performance silicon solutions for communications, computing, and industrial markets.

The IDT70261 product line was designed specifically for deterministic, low-latency inter-processor communication in harsh-environment embedded systems requiring hardware-accelerated memory sharing and resource arbitration.

FAQ

What is the maximum operating temperature range for the 70261L55PFI?

The 70261L55PFI is rated for industrial operation from −40°C to +85°C ambient temperature. This specification is validated across all DC and AC electrical parameters in the datasheet, including tAA = 55 ns max, ISB3 = 0.2 mA typ., and VIL = 0.8 V max. The device uses CMOS process technology optimized for thermal stability in uncontrolled environments.

Does the 70261L55PFI support true simultaneous access to the same memory address?

Yes, the 70261L55PFI implements true dual-port memory cells that allow concurrent read/write operations to identical addresses. When contention occurs, on-chip arbitration asserts BUSY on the lower-priority port, blocking write execution until BUSY deasserts. This behavior is guaranteed by tBDD ≤ 40 ns and tAPS = 5 ns timing parameters in the datasheet.

How does the interrupt function work in the 70261L55PFI?

The 70261L55PFI uses dedicated SRAM locations 3FFE_H (left port) and 3FFF_H (right port) as interrupt mailboxes. Writing to 3FFF_H from the left port asserts INTR; reading 3FFF_H from the right port clears it. Similarly, 3FFE_H controls INTL. Latency is bounded by tINS ≤ 40 ns and tINR ≤ 40 ns per the datasheet.

Can the 70261L55PFI be used in a 32-bit memory system?

Yes, the 70261L55PFI supports 32-bit expansion via Master/Slave configuration using the M/S pin. When cascading two devices, the master's BUSY output connects to the slave's BUSY input, enabling coordinated arbitration across 32-bit words without external logic. This is explicitly documented in the functional block diagram and pin configuration notes.

What is the standby power consumption of the 70261L55PFI?

The 70261L55PFI achieves 0.2 mA typical standby current (ISB3) when both ports are disabled with CMOS-level inputs (CE > VCC − 0.2 V). This ultra-low power state is enabled by internal power-gating circuitry controlled solely by chip enable signals-no additional control pins or sequencing required. Measured at VCC = 5.0 V and TA = +25°C per Table 10.