Renesas 70261L35PF8

Overview

70261L35PF8 from IDT (Integrated Device Technology) is a high-speed 16K × 16 dual-port static RAM with interrupt and semaphore support, designed for real-time inter-processor communication in embedded systems. It features 35 ns maximum read cycle time, 1 mA typical standby current, TTL-compatible 5 V ±10% operation, and 100-pin TQFP packaging. It enables simultaneous asynchronous access to shared memory between two independent bus domains - e.g., DSP + microcontroller co-processing.

For engineers reviewing the 70261L35PF8 datasheet, 70261L35PF8 pinout, 70261L35PF8 application, or 70261L35PF8 equivalent, key selection criteria include port arbitration timing (tBDD ≤ 35 ns), interrupt flag latency (tINS ≤ 25 ns), dual-byte enable control (UBL/LBL), and industrial temperature support (−40°C to +85°C).

Technical Context

The 70261L35PF8 implements fully asynchronous dual-port architecture with independent left/right address, control, and I/O buses. Its on-chip arbitration logic resolves contention via BUSY flag assertion (push-pull output) when both ports access the same address, with priority determined by tAPS (5 ns setup). Semaphore signaling uses dedicated A0–A2 addressing and SEM pin control to coordinate resource locking across ports.

Interrupt generation is memory-mapped: writing to address 3FFF_H asserts INTR (right port flag), while writing to 3FFE_H asserts INTL (left port flag); flags are cleared by reading those same addresses. All control signals - CE, R/W, OE, UB/LB - operate at TTL voltage levels with no internal latching.

Key Specifications

Pinout & Package

70261L35PF8 is housed in a 100-pin TQFP (PNG100) package 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 CY7C028V-35AC and R1EX24016AS0C-35, the 70261L35PF8 delivers integrated arbitration, interrupt, and semaphore functions in a single 5 V device - reducing component count by ≥3 and eliminating timing-critical external logic design.

Availability

70261L35PF8 is available at Aetrix Electronics and suitable for industrial automation, avionics data concentrators, and telecom line card buffering requiring stable component supply across extended product lifecycles.

Supply support for 70261L35PF8 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 sensor solutions, acquired by Renesas in 2019.

The IDT70261 family was engineered for deterministic, low-latency inter-processor communication in real-time embedded systems - emphasizing hardware arbitration, interrupt signaling, and seamless 5 V bus integration.

FAQ

What is the operating temperature range supported by the 70261L35PF8?

The 70261L35PF8 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 (page 3) and DC Electrical Characteristics (page 5) of the official datasheet. The part meets this range under full functionality - including all timing parameters, interrupt behavior, and standby current - without derating.

Does the 70261L35PF8 support true simultaneous read/write to the same memory address?

Yes, the 70261L35PF8 implements true dual-ported memory cells that allow concurrent access to the same location. However, when both ports attempt write operations to identical addresses, the on-chip arbitration logic asserts BUSY to stall one port. Reads remain unaffected - valid data appears within tAA (≤35 ns) regardless of concurrent activity on the opposite port.

How does the interrupt function work on the 70261L35PF8?

The 70261L35PF8 uses memory-mapped interrupt flags: writing to address 3FFF_H asserts INTR (right port flag), and writing to 3FFE_H asserts INTL (left port flag). Flags are cleared by reading those same addresses. This behavior is defined in Truth Table III (page 14) and Functional Description (page 15), enabling hardware-triggered ISR entry without polling.

Can the 70261L35PF8 be used in a 32-bit data path configuration?

Yes. The 70261L35PF8 supports 32-bit expansion using master/slave cascading: one device configured as MASTER (M/S = H) provides BUSY output, while others as SLAVE (M/S = L) accept BUSY input. This is explicitly described in the Features section (page 1) and Functional Block Diagram (page 1), enabling full-speed error-free 32-bit-or-more word systems without discrete logic.

What is the standby current consumption of the 70261L35PF8?

The 70261L35PF8 achieves 0.2 mA typical full-standby current (ISB3) when both ports are disabled with CMOS-level inputs (CE > VCC − 0.2 V). This value is specified in Table 10 (page 5) and distinguishes the "L" (low-power) variant from the "S" version (1.0 mA typ.). It applies across the full industrial temperature range.