Renesas 70V631S12PRFI8

Overview

70V631S12PRFI8 from IDT (Integrated Device Technology) is a high-speed, fully asynchronous 256K × 18 dual-port static RAM with independent left/right ports, 12 ns max access time (industrial grade), 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port via OPT pins - used in real-time inter-processor communication, FPGA co-processor buffering, and legacy bus bridging where simultaneous read/write to same memory location is required.

For engineers reviewing the 70V631S12PRFI8 datasheet, 70V631S12PRFI8 pinout, 70V631S12PRFI8 application, or 70V631S12PRFI8 equivalent, key selection criteria include true dual-port arbitration logic, BUSY/INT semaphore support, JTAG omission on TQFP packages, industrial temperature range (–40°C to +85°C), and compatibility with 128-pin TQFP footprint for space-constrained embedded control systems.

Technical Context

The 70V631S12PRFI8 implements fully asynchronous operation on both ports with no clock dependency, enabling deterministic timing across heterogeneous subsystems. Its on-chip arbitration logic resolves port contention using BUSY flag signaling, while semaphore registers (A0–A2 addressable) provide hardware-level mutual exclusion for shared resource access.

Each port supports independent power domain configuration: VDD fixed at 3.3 V ±150 mV, while VDDQL/VDDQR are set to either 3.3 V ±150 mV or 2.5 V ±100 mV based on OPTL/OPTR logic levels - allowing mixed-voltage system integration without level shifters. The device operates in MASTER/SLAVE cascading mode for 36-bit+ word expansion using M/S pin control.

Key Specifications

Pinout & Package

70V631S12PRFI8 is housed in a 128-pin Thin Quad Flatpack (TQFP) package with 0.5 mm lead pitch and 14 mm × 20 mm body size. All VDD pins require 3.3 V supply; VDDQL/VDDQR must match OPTL/OPTR logic state (3.3 V if VIH, 2.5 V if VIL); all VSS pins connect to ground.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV18-125BZI and AS7C3256B-12JIN, the 70V631S12PRFI8 uniquely delivers asynchronous operation with per-port I/O voltage selection, integrated BUSY arbitration, and MASTER/SLAVE cascading - making it the only option for deterministic real-time inter-processor communication in mixed-voltage industrial systems.

Availability

70V631S12PRFI8 is available at Aetrix Electronics and suitable for industrial PLC data exchange, FPGA-CPU shared memory buffering, and legacy bus bridge interfaces requiring stable component supply, long-term lifecycle support, and guaranteed industrial temperature performance.

Supply support for 70V631S12PRFI8 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 timing, memory interface, and RF solutions for communications, computing, and industrial markets.

The 70V631S12PRFI8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, engineered specifically for real-time inter-processor communication, FPGA co-processing, and deterministic data exchange in industrial and telecom infrastructure.

FAQ

What is the maximum operating temperature range for the 70V631S12PRFI8?

The 70V631S12PRFI8 is rated for industrial temperature operation from –40°C to +85°C. This specification is confirmed in the "Recommended Operating Temperature and Supply Voltage" table (page 7 of the datasheet), where the "Industrial" grade explicitly lists this range under ambient temperature (TA). It is not rated for extended or military temperature ranges.

Does the 70V631S12PRFI8 support JTAG boundary scan?

No, the 70V631S12PRFI8 does not support JTAG boundary scan when packaged in the 128-pin TQFP (PK-128). The datasheet explicitly states on page 1: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package." JTAG pins (TMS, TCK, TRST, TDI, TDO) are present only in the 208-ball and 256-ball BGA variants.

How does the M/S pin affect BUSY functionality in the 70V631S12PRFI8?

In the 70V631S12PRFI8, the M/S pin configures BUSY behavior: when M/S = VIH, the device operates as Master and BUSYL/BUSYR are outputs asserting during port contention; when M/S = VIL, it operates as Slave and BUSYL/BUSYR become inputs that must be driven externally to inhibit writes. This is defined in Note 1 on page 2 and timing diagrams on pages 15–16.

Can both ports of the 70V631S12PRFI8 operate at different I/O voltages simultaneously?

Yes. The 70V631S12PRFI8 supports independent I/O voltage selection per port: OPTL sets left-port VDDQL (3.3 V or 2.5 V), and OPTR sets right-port VDDQR (3.3 V or 2.5 V). The datasheet confirms this on page 5 ("Pin Names") and page 7 ("Recommended DC Operating Conditions"), stating "both ports can operate at 3.3V levels, both can operate at 2.5V levels, or either can operate at 3.3V with the other at 2.5V."

What is the minimum pulse width required for reliable write operations on the 70V631S12PRFI8?

The minimum write pulse width (tWP) for the 70V631S12PRFI8 is 10 ns, as specified in the AC Electrical Characteristics table (page 10, 70V631S12 column). This applies to both CE-controlled and R/W-controlled write cycles. The datasheet further clarifies in Note 8 on page 12 that if OE = VIL during an R/W-controlled write, the effective pulse must be the larger of tWP or (tWZ + tDW) to ensure proper driver turn-off and data setup.