Renesas 70261L20PFI

Overview

70261L20PFI 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 (−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/right ports in real-time communication buffers and shared-memory interprocessor systems.

For engineers reviewing the 70261L20PFI datasheet, 70261L20PFI pinout, 70261L20PFI application, or 70261L20PFI equivalent, key selection criteria include port arbitration timing (tAPS = 5 ns), BUSY flag response (tBAA ≤ 20 ns), low standby power (ISB3 = 0.2 mA typ.), and TTL-compatible 5V I/O for legacy bus interfacing.

Technical Context

The 70261L20PFI implements full hardware port arbitration using push-pull BUSY outputs and Master/Slave select (M/S) to coordinate concurrent access to identical memory addresses. Its on-chip semaphore logic supports eight independent flags addressed via A0–A2, writable through I/O0 and readable across all 16 I/O lines.

Interrupt signaling uses dedicated mailbox addresses (3FFE_H for INTL, 3FFF_H for INTR) with set/reset controlled by CE/R/W/OE combinations per Truth Table III. The device operates fully asynchronously per port, with separate CE, R/W, OE, UB/LB, and SEM controls enabling byte-selective, low-latency memory transactions without external glue logic.

Key Specifications

Pinout & Package

70261L20PFI 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 externally 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 IDT70V261S20PFI, the 70261L20PFI uniquely combines industrial temperature operation, integrated semaphore logic, and 0.2 mA full-standby current-making it optimal for ruggedized, self-contained dual-processor systems where power, reliability, and hardware synchronization are critical.

Availability

70261L20PFI is available at Aetrix Electronics and suitable for industrial PLCs, avionics data concentrators, medical imaging subsystems, and real-time DSP co-processing platforms requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70261L20PFI 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

Renesas Electronics (formerly Integrated Device Technology) is a global semiconductor leader specializing in microcontrollers, analog, power management, and memory solutions for industrial, automotive, and communications markets.

The IDT70261 product line was engineered specifically for deterministic inter-processor communication, delivering hardware-accelerated arbitration, interrupt, and semaphore features in a single 5V dual-port SRAM package for real-time embedded systems.

FAQ

What is the maximum operating temperature range for the 70261L20PFI?

The 70261L20PFI is rated for industrial temperature operation from −40°C to +85°C. This specification is confirmed in the "Maximum Operating Temperature and Supply Voltage" table (Table 2) and validated across all AC/DC electrical characteristics in the datasheet. The 70261L20PFI maintains full 20 ns access time and functional integrity across this entire range.

Does the 70261L20PFI support true simultaneous access to the same memory location from both ports?

Yes, the 70261L20PFI implements true dual-ported memory cells that permit simultaneous read/write access to identical addresses. When contention occurs, on-chip arbitration asserts BUSY on the later-arriving port, allowing the first access to complete without data corruption. This behavior is documented in the Functional Block Diagram and Truth Table IV.

How does the interrupt function work in the 70261L20PFI?

The 70261L20PFI uses dedicated mailbox addresses: writing to 3FFF_H from the left port asserts INTR, and writing to 3FFE_H from the right port asserts INTL. Clearing is performed by reading those same addresses. This mechanism is defined in Truth Table III and the Functional Description section, with tINS ≤ 20 ns interrupt set time guaranteed.

What is the standby current consumption of the 70261L20PFI in full power-down mode?

In full standby mode (ISB3), where both ports have CE driven high and all inputs held at valid CMOS levels, the 70261L20PFI draws 0.2 mA typical current. This value is specified in Table 10 under "ISB3 Full Standby Current (Both Ports – All CMOS Level Inputs)" for the L version at industrial temperature.

Can the 70261L20PFI be used in a Master/Slave configuration for wider data buses?

Yes, the 70261L20PFI supports cascaded Master/Slave operation using the M/S pin: M/S = H configures BUSY as output (Master), while M/S = L configures BUSY as input (Slave). This enables seamless expansion to 32-bit or wider word systems without external logic, as described in the Features list and Functional Block Diagram.