Renesas 70T631S10BF8

Overview

70T631S10BF8 from Integrated Device Technology is a high-speed 256K × 18-bit asynchronous dual-port static RAM with true simultaneous access to the same memory location, 10 ns read cycle time, single 2.5 V core supply, and selectable 2.5 V/3.3 V I/O interface per port. It supports RapidWrite Mode for back-to-back writes and on-chip semaphore arbitration-used in real-time inter-processor communication systems requiring deterministic data exchange between independent bus domains.

For engineers reviewing the 70T631S10BF8 datasheet, 70T631S10BF8 pinout, 70T631S10BF8 application, or 70T631S10BF8 equivalent, key selection criteria include its 208-ball fine-pitch BGA package, industrial temperature support (–40°C to +85°C), JTAG-compliant IEEE 1149.1 testability, and Master/Slave cascading capability for 36-bit+ memory expansion without external logic.

Technical Context

This device implements fully asynchronous dual-port architecture with independent address, control, and I/O buses per port, enabling concurrent read/write operations without internal arbitration delay. Its on-chip port arbitration logic resolves contention via BUSY flag signaling and hardware semaphore registers accessible at A0–A2.

RapidWrite Mode eliminates R/W pulse requirements between consecutive writes by defining write end via address transition-reducing timing complexity at 10 ns cycle times. The OPTL/OPTR pins independently configure each port's I/O voltage (2.5 V or 3.3 V), while VDD remains fixed at 2.5 V for core logic.

Key Specifications

Pinout & Package

70T631S10BF8 is housed in a 208-ball fine-pitch Ball Grid Array (BF208 package), body size ≈15 mm × 15 mm × 1.4 mm, 0.8 mm ball pitch. All VDD pins require 2.5 V; VDDQ pins must match OPT pin state (2.5 V if OPT = VSS, 3.3 V if OPT = VDD).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1365KV18 and 21CSM020, the 70T631S10BF8 delivers superior real-time determinism via 10 ns access, per-port voltage flexibility, and integrated semaphore arbitration-making it optimal for safety-critical or high-throughput inter-processor communication where timing predictability and hardware-enforced coherency are mandatory.

Availability

70T631S10BF8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and medical imaging applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 70T631S10BF8 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, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs for communications, computing, and industrial markets.

The 70T633/1 family-including 70T631S10BF8-is designed for high-reliability, low-latency inter-processor communication in systems demanding true dual-port concurrency, hardware synchronization, and mixed-voltage interoperability.

FAQ

What is the memory organization of the 70T631S10BF8?

The 70T631S10BF8 implements a 256K × 18-bit asynchronous dual-port SRAM array. Address line A18 is a no-connect (NC) per datasheet note 1, confirming its 256K depth (A0–A17). This yields 4.608 Mbit total capacity, with independent 18-bit I/O paths on left and right ports for true simultaneous access.

Does the 70T631S10BF8 support JTAG boundary-scan testing?

Yes, the 70T631S10BF8 supports IEEE 1149.1 JTAG boundary-scan in its BF208 package. Pins TCK, TMS, TDI, TDO, and TRST are dedicated to this function and remain operational even when ZZL/ZZR assert sleep mode-enabling in-system test and debug without disrupting core functionality.

How does RapidWrite Mode work in the 70T631S10BF8?

RapidWrite Mode in the 70T631S10BF8 allows consecutive write operations without pulsing R/W, CE, or byte enables between cycles. Write termination is defined by the ending address transition-not R/W deassertion-reducing controller timing burden. Input data setup/hold (tDW/tDH) reference this address edge, and tAS/tWR apply only when switching between read and write modes.

What is the role of the OPTL and OPTR pins on the 70T631S10BF8?

OPTL and OPTR independently configure the I/O voltage level for each port: setting OPTX to VSS (0 V) selects 2.5 V I/O operation with corresponding VDDQX = 2.5 V; setting OPTX to VDD (2.5 V) selects 3.3 V I/O operation with VDDQX = 3.3 V. This enables mixed-voltage interfacing-for example, connecting the left port to a 3.3 V DSP and the right port to a 2.5 V FPGA.

Can the 70T631S10BF8 operate in industrial temperature range?

Yes, the 70T631S10BF8 is qualified for industrial temperature operation from –40°C to +85°C. This rating applies to the 10 ns speed grade (70T631S10) and is explicitly stated in the "Recommended Operating Temperature" table (page 7) and "AC Electrical Characteristics" notes (page 10) of the official datasheet.