Renesas 70T631S12BF8

Overview

70T631S12BF8 from Integrated Device Technology is a high-speed 256K × 18 asynchronous dual-port static RAM with true simultaneous access to the same memory location, 12 ns maximum access 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 70T631S12BF8 datasheet, 70T631S12BF8 pinout, 70T631S12BF8 application, or 70T631S12BF8 equivalent, key selection criteria include dual-port arbitration logic, BUSY/INT flag behavior in MASTER/SLAVE configurations, sleep mode current (≤10 mA), JTAG-compliant IEEE 1149.1 test support, and BGA-208 package compatibility with industrial temperature range (–40°C to +85°C).

Technical Context

This device implements fully asynchronous dual-port operation with independent address, control, and data buses per port-enabling concurrent read/write access without external synchronization logic. Its on-chip arbitration resolves port contention via hardware semaphore signaling and BUSY flag assertion during overlapping accesses to identical addresses.

The 70T631S12BF8 supports flexible I/O voltage configuration: OPTL/OPTR pins select either 2.5 V or 3.3 V levels per port, while VDD remains fixed at 2.5 V. It includes RapidWrite Mode (address-triggered write termination), Master/Slave cascading for 36-bit+ data width expansion, and IEEE 1149.1 JTAG boundary scan in BGA-208 packaging.

Key Specifications

Pinout & Package

70T631S12BF8 is housed in a 208-ball fine-pitch Ball Grid Array (BGA) package with 0.8 mm ball pitch and 15 mm × 15 mm body size. All VDD pins require 2.5 V; VDDQ pins must match selected I/O voltage (2.5 V or 3.3 V) per port based on OPTL/OPTR state.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV18 and 72T36120L12TFI, the 70T631S12BF8 uniquely integrates per-port voltage selection, RapidWrite Mode, and hardware semaphore logic in a JTAG-enabled BGA-208 package-making it optimal for compact, mixed-voltage, multi-processor systems requiring deterministic arbitration.

Availability

70T631S12BF8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, avionics data concentrators, and high-speed test equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70T631S12BF8 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 solutions for communications, computing, and industrial markets.

The 70T631S12BF8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for deterministic inter-processor communication in real-time embedded systems where latency, arbitration integrity, and mixed-voltage interoperability are critical.

FAQ

What is the memory organization of the 70T631S12BF8?

The 70T631S12BF8 implements a 256K × 18-bit asynchronous dual-port SRAM architecture. Address line A18 is designated No Connect (NC), confirming the 256K depth (A0–A17 = 18 address bits). This yields 4.5 Mbit total capacity with independent left and right ports supporting simultaneous access to any memory location.

Does the 70T631S12BF8 support both 2.5 V and 3.3 V I/O interfaces?

Yes, the 70T631S12BF8 supports selectable I/O voltage per port via OPTL and OPTR pins. Setting OPTX to VSS configures that port for 2.5 V I/O operation with VDDQX = 2.5 V; setting OPTX to VDD configures it for 3.3 V I/O with VDDQX = 3.3 V. The core VDD remains fixed at 2.5 V regardless of I/O selection.

How does the BUSY flag operate in MASTER vs. SLAVE configuration on the 70T631S12BF8?

On the 70T631S12BF8, BUSYL and BUSYR behave as outputs when M/S = VIH (Master mode), signaling arbitration conflict during simultaneous access. When M/S = VIL (Slave mode), BUSY pins become inputs - allowing external master to drive the flag and coordinate access. This dual-role behavior is essential for cascaded MASTER/SLAVE topologies.

What is RapidWrite Mode and how does it benefit system design with the 70T631S12BF8?

RapidWrite Mode on the 70T631S12BF8 allows consecutive write operations without pulsing R/W, CE, or byte enables between cycles. Write termination is triggered by the ending address transition, not control signal deassertion. This eliminates narrow pulse generation challenges and simplifies timing-critical address sequencing in high-throughput buffering applications.

Is JTAG boundary scan supported on the 70T631S12BF8, and what are the requirements?

Yes, the 70T631S12BF8 supports IEEE 1149.1 JTAG boundary scan in its BGA-208 package. Required pins are TCK, TMS, TDI, TDO, and TRST. JTAG remains functional during sleep mode (ZZ asserted), but boundary scan operation is not recommended while ZZ is active due to reduced internal clocking.