Renesas 70T631S10BCI

Overview

70T631S10BCI 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 via independent left/right ports, 10 ns max read cycle time, single 2.5 V core supply, and selectable 2.5 V/3.3 V I/O interface per port - used in real-time inter-processor communication and FPGA co-processor buffering.

For engineers reviewing the 70T631S10BCI datasheet, 70T631S10BCI pinout, 70T631S10BCI application, or 70T631S10BCI equivalent, this page delivers verified specifications, BGA-208 package mapping, RapidWrite Mode timing behavior, semaphore arbitration logic, and industrial-grade (–40°C to +85°C) operation details critical for deterministic multi-core memory sharing designs.

Technical Context

The 70T631S10BCI implements fully asynchronous dual-port architecture with on-chip port arbitration, hardware semaphore signaling, and independent byte controls (UBL/LBL, UBR/LBR) enabling multiplexed bus compatibility. It supports JTAG IEEE 1149.1 boundary scan in BGA-208 packaging.

Its RapidWrite Mode eliminates R/W pulse requirement between consecutive writes by defining write end via address transition, reducing control logic overhead. BUSY flag operates as output in Master mode (M/S = VIH) and input in Slave mode (M/S = VIL), enabling depth expansion without external logic.

Key Specifications

Pinout & Package

70T631S10BCI uses the BF208 208-ball fine-pitch BGA package (15 mm × 15 mm, 0.8 mm pitch). Pin functions are asymmetrically distributed across left (L) and right (R) ports, with dedicated VDD, VDDQ, VSS, and JTAG balls. All VDD pins require 2.5 V; VDDQ voltage per port depends on OPTL/OPTR setting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-10BGXI and IDT70V27L15PF8, the 70T631S10BCI uniquely combines industrial temperature range, per-port I/O voltage flexibility, hardware semaphore, and RapidWrite Mode - making it the only viable option for deterministic, mixed-voltage, real-time dual-processor memory sharing.

Availability

70T631S10BCI is available at Aetrix Electronics and suitable for industrial motion control, telecom line card design, avionics display systems, and FPGA co-processor buffering requiring stable component supply across extended product lifecycles.

Supply support for 70T631S10BCI 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 70T631S10BCI belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for deterministic inter-processor communication, real-time control buffering, and FPGA-ASIC bridging in industrial and telecom infrastructure.

FAQ

What is the memory size and organization of the 70T631S10BCI?

The 70T631S10BCI is organized as 256K × 18 bits (4.5 Mbit total), with separate 18-bit address and data buses for left and right ports. Address line A18 is a no-connect (NC), confirming it does not support the 512K × 18 variant - the 70T631S10BCI is strictly the 256K version. This fixed configuration simplifies address decoding in systems requiring deterministic 256K buffers.

Does the 70T631S10BCI support both 2.5 V and 3.3 V I/O interfaces simultaneously?

Yes - the 70T631S10BCI supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL to VSS configures the left port for 2.5 V I/O (requiring VDDQL = 2.5 V), while setting OPTR to VDD configures the right port for 3.3 V I/O (requiring VDDQR = 3.3 V). This enables direct interfacing with heterogeneous logic families without external level shifters.

What is the function of the BUSY pin on the 70T631S10BCI?

On the 70T631S10BCI, BUSYL and BUSYR serve dual roles: they act as outputs when the device is configured as Master (M/S = VIH), signaling arbitration conflict during concurrent access; and as inputs when configured as Slave (M/S = VIL), accepting busy status from a master device. This bidirectional capability enables scalable master/slave cascading without additional control logic.

How does RapidWrite Mode operate on the 70T631S10BCI?

RapidWrite Mode on the 70T631S10BCI allows back-to-back write operations without pulsing R/W, CE, or byte enables between cycles. The write cycle end is defined by the address transition instead of control signal deassertion. This reduces timing complexity in FPGA-based controllers and eliminates narrow pulse generation - provided tAAS ≤ 1 ns and tARF ≥ 1.5 V/ns are met for reliable address skew control.

Is the 70T631S10BCI compatible with JTAG boundary scan testing?

Yes - the 70T631S10BCI supports IEEE 1149.1 JTAG boundary scan in its BF208 (208-ball fine-pitch BGA) package. Pins TDI, TDO, TCK, TMS, and TRST are dedicated and electrically compliant. Boundary scan is functional even during sleep mode (ZZ asserted), though IDT recommends avoiding JTAG operation in sleep mode per datasheet Note 4.