Renesas 70261L20PF8

Overview

70261L20PF8 from IDT (now Renesas) is a high-speed 16K × 16 true dual-port static RAM with interrupt and semaphore logic, operating at 20 ns max access time over industrial temperature range (–40°C to +85°C), powered by single 5V ±10% supply, and packaged in 100-pin TQFP. It enables simultaneous asynchronous read/write access from independent left and right ports - used in real-time interprocessor communication, video frame buffers, and military/aerospace data acquisition systems.

For engineers reviewing the 70261L20PF8 datasheet, 70261L20PF8 pinout, 70261L20PF8 application, or 70261L20PF8 equivalent, key selection considerations include BUSY/INT flag timing (tBAA ≤ 20 ns, tINS ≤ 20 ns), low standby current (ISB3 = 0.2 mA typ.), TTL-compatible I/O, and master/slave cascading support for 32-bit+ bus expansion.

Technical Context

The 70261L20PF8 implements fully asynchronous dual-port architecture with on-chip arbitration logic that resolves contention via BUSY flag assertion when both ports access identical addresses. Its port-to-port delay (tWDD ≤ 45 ns, tDDD ≤ 30 ns) ensures deterministic handshake timing between processors.

It integrates dedicated semaphore registers (8 flags, addressed by A0–A2) accessible via CE = VIH / SEM = VIL, and interrupt mailbox functionality using fixed addresses 3FFE_H (left INTL) and 3FFF_H (right INTR), with push-pull INT/BUSY outputs and full hardware semaphore signaling without external logic.

Key Specifications

Pinout & Package

70261L20PF8 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 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 CY7C1362BV33-200BZXI and IDT70V261S20PF8, the 70261L20PF8 uniquely delivers industrial-temperature operation, integrated hardware semaphores, and 5V compatibility - making it irreplaceable in legacy ruggedized systems requiring zero-software arbitration.

Availability

70261L20PF8 is available at Aetrix Electronics and suitable for real-time interprocessor communication, video frame buffering, and industrial PLC data exchange requiring stable component supply across extended lifecycle programs.

Supply support for 70261L20PF8 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), now part of Renesas Electronics, is a semiconductor leader specializing in high-performance memory, timing, and interface solutions for communications, computing, and industrial markets.

The 70261L20PF8 belongs to IDT's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency interprocessor communication in mission-critical embedded systems where hardware arbitration and interrupt signaling are mandatory.

FAQ

What is the maximum access time specification for the 70261L20PF8?

The 70261L20PF8 has a maximum access time of 20 ns across the full industrial temperature range (–40°C to +85°C). This applies to address access (tAA), chip enable access (tACE), and byte enable access (tABE), ensuring consistent timing behavior in demanding thermal environments. The 70261L20PF8 meets this spec under VCC = 5.0 V ±10% and load conditions defined in the official AC test setup.

Does the 70261L20PF8 support true simultaneous read/write operations to the same memory location?

Yes, the 70261L20PF8 implements true dual-ported memory cells that allow independent, asynchronous access from left and right ports - including simultaneous read and write to identical addresses. When contention occurs, on-chip arbitration asserts BUSY on the later-arriving port, preserving data integrity without external logic. This behavior is intrinsic to the 70261L20PF8 silicon architecture.

How does the interrupt functionality work on the 70261L20PF8?

The 70261L20PF8 uses fixed memory-mapped addresses for interrupt signaling: writing to 3FFF_H sets the right-port INTR flag, and writing to 3FFE_H sets the left-port INTL flag. Reading those addresses clears the respective flags. The 70261L20PF8 generates push-pull interrupt pulses with tINS ≤ 20 ns, enabling immediate processor response without polling overhead.

What is the standby current consumption of the 70261L20PF8 in full power-down mode?

In full standby mode (ISB3), where both ports are disabled with CMOS-level inputs (CE > VCC – 0.2 V, all inputs at rail), the 70261L20PF8 draws only 0.2 mA typical current. This ultra-low quiescent draw is specified over the full industrial temperature range and enables energy-efficient operation in battery-backed or thermally constrained systems.

Can multiple 70261L20PF8 devices be cascaded to form a 32-bit-wide memory interface?

Yes, the 70261L20PF8 supports master/slave cascading via the M/S pin to expand data bus width beyond 16 bits. When configured as master (M/S = H), BUSY is an output; as slave (M/S = L), BUSY becomes an input. This allows seamless 32-bit or wider memory systems without additional discrete logic - a core capability built into the 70261L20PF8 architecture.