Renesas 70T651S12BF

Overview

70T651S12BF from Integrated Device Technology is a high-speed 256K × 36-bit asynchronous dual-port static RAM with independent left/right ports, 12 ns maximum access time, 2.5 V core supply, and selectable 2.5 V/3.3 V I/O interface per port-designed for real-time inter-processor communication in telecom switching fabric and packet buffer applications.

For engineers reviewing the 70T651S12BF datasheet, 70T651S12BF pinout, 70T651S12BF application, or 70T651S12BF equivalent, this page delivers verified pin mapping, true dual-port arbitration behavior, RapidWrite timing constraints, industrial-grade (-40°C to +85°C) operation, and direct alternatives for memory expansion in master/slave configurations.

Technical Context

The 70T651S12BF implements fully asynchronous dual-port architecture with on-chip arbitration logic and hardware semaphore support across both ports. It enables simultaneous read/write access to the same memory location without external logic, using separate CE0/CE1, R/WL/R/WR, OEL/OER, and BE0–BE3 controls per port.

Each port supports independent power domains: fixed 2.5 V VDD core and configurable VDDQ (2.5 V or 3.3 V) selected via OPTL/OPTR pins. JTAG IEEE 1149.1 compliance enables boundary-scan testing, while ZZL/ZZR sleep mode reduces current to ≤10 mA per port during idle cycles.

Key Specifications

Pinout & Package

70T651S12BF is housed in a 208-ball fpBGA (BF208) package with 0.8 mm pitch and 15 mm × 15 mm body size. Ball assignments follow JEDEC MO-245 standard; all VDD pins require 2.5 V, VDDQ pins routed per OPT setting, and VSS pins tied to ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33 and 72T36125, the 70T651S12BF uniquely combines per-port I/O voltage selection, RapidWrite mode, and master/slave cascading in a 208-ball fpBGA - enabling lower-system-cost implementations in mixed-voltage, high-throughput embedded memory subsystems.

Availability

70T651S12BF is available at Aetrix Electronics and suitable for telecom packet buffering, real-time inter-processor communication, and industrial PLC data exchange requiring stable component supply across extended product lifecycles.

Supply support for 70T651S12BF 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

Integrated Device Technology (IDT), now part of Renesas Electronics, specializes in high-performance timing, memory interface, and RF products for communications and computing infrastructure.

The 70T651S12BF belongs to IDT's high-speed dual-port SRAM family, engineered for deterministic latency, low-power inter-processor messaging, and seamless integration into telecom, industrial, and medical real-time systems.

FAQ

What is the maximum operating frequency supported by the 70T651S12BF?

The 70T651S12BF is an asynchronous SRAM and does not operate on a clock signal; its performance is defined by access time rather than frequency. With a 12 ns maximum access time (tAA), it supports effective throughput up to ~83 MHz in tightly controlled read/write cycles - verified under industrial conditions (-40°C to +85°C) with 2.5 V VDD and appropriate VDDQ.

Does the 70T651S12BF support true simultaneous access to the same memory address from both ports?

Yes, the 70T651S12BF implements true dual-port memory cells that permit concurrent read and write operations to the identical address location. This capability is enabled by internal cell architecture-not external arbitration-and is guaranteed across the full industrial temperature range without data corruption or bus contention.

How does RapidWrite Mode function in the 70T651S12BF, and what timing parameters change?

In RapidWrite Mode, the 70T651S12BF eliminates the need to toggle R/W between write cycles. Instead, the address transition defines the end of each write, and tAS/tWR become irrelevant during consecutive writes. The 70T651S12BF maintains full tWC, tDW, and tDH compliance - simplifying controller logic while preserving data integrity at 12 ns cycle boundaries.

Can the left and right ports of the 70T651S12BF operate at different I/O voltages simultaneously?

Yes - OPTL and OPTR are independent inputs. Setting OPTL = VSS and OPTR = VDD configures the left port for 2.5 V I/O levels (requiring VDDQL = 2.5 V) and the right port for 3.3 V I/O levels (requiring VDDQR = 3.3 V). This mixed-voltage operation is fully supported and characterized in the 70T651S12BF datasheet across commercial and industrial grades.

What is the role of the M/S pin in 70T651S12BF master/slave configurations?

The M/S pin configures the 70T651S12BF as either master (M/S = VIH → BUSYR/BUSYL outputs active) or slave (M/S = VIL → BUSYR/BUSYL inputs). In cascaded systems, one device acts as master to drive BUSY flags to slaves, enabling depth expansion beyond 36 bits without external logic - a key feature confirmed for the 70T651S12BF in IDT application note AN-5632.