Renesas 70V631S15PRF

Overview

70V631S15PRF from IDT (now Renesas) is a high-speed, fully asynchronous 256K × 18-bit dual-port static RAM with independent left/right ports, 15 ns max access time (commercial grade), LVTTL-compatible 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port via OPT pins. It enables simultaneous read/write to the same memory location in real-time systems such as network packet buffers and FPGA co-processor interfaces.

For engineers reviewing the 70V631S15PRF datasheet, 70V631S15PRF pinout, 70V631S15PRF application, or 70V631S15PRF equivalent, this page delivers verified specifications, validated pin functions for the 128-pin TQFP package, industrial-grade timing behavior, on-chip semaphore arbitration, and direct alternatives for bus-width expansion or voltage-flexible dual-port memory designs.

Technical Context

The 70V631S15PRF implements true dual-port SRAM architecture with separate address, data, and control buses per port, enabling concurrent access without external arbitration logic. Its on-chip port arbitration logic resolves contention via BUSY flag generation and supports MASTER/SLAVE cascading for 36-bit+ word systems using M/S pin configuration.

It features full hardware semaphore signaling across ports (8 flags, addressed by A0–A2), JTAG test interface (excluded only in 128-pin TQFP), and automatic power-down controlled independently per port via CE0/CE1. Core operates at fixed 3.3 V ±150 mV; I/O voltage per port is selected by OPTL/OPTR (3.3 V or 2.5 V) with corresponding VDDQL/VDDQR supply.

Key Specifications

Pinout & Package

70V631S15PRF is housed in a 128-pin Thin Quad Flatpack (TQFP) package (PKG128), measuring approximately 14 mm × 20 mm × 1.4 mm. All VDD pins must be connected to 3.3 V; VDDQL/VDDQR must match OPTL/OPTR selection (3.3 V or 2.5 V); all VSS pins require solid ground connection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-15ZXI and AS7C3256B-15JCIN, the 70V631S15PRF uniquely delivers per-port I/O voltage selection, on-chip BUSY arbitration, and hardware semaphore support-reducing BOM count and firmware complexity in heterogeneous, real-time embedded systems.

Availability

70V631S15PRF is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and avionics applications requiring stable component supply, long-term lifecycle support, and guaranteed commercial-grade timing performance.

Supply support for 70V631S15PRF 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

IDT (Integrated Device Technology), now part of Renesas Electronics, is a fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 70V631S15PRF belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for real-time, contention-prone systems requiring deterministic latency, hardware arbitration, and flexible voltage interfacing.

FAQ

What is the maximum operating temperature range for the 70V631S15PRF?

The 70V631S15PRF is specified for commercial operation from 0°C to +70°C. While the datasheet notes industrial-grade variants (e.g., 70V631S12) support –40°C to +85°C, the 70V631S15PRF suffix explicitly denotes the commercial-speed, commercial-temperature version. Always verify ambient and junction temperature derating in final PCB layout.

Does the 70V631S15PRF support JTAG boundary-scan testing?

No, the 70V631S15PRF in the 128-pin TQFP package does not support JTAG. The datasheet explicitly states: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package." JTAG functionality is available only in the 208-ball and 256-ball BGA variants (e.g., 70V631S15PFI, 70V631S15PGI).

How does the M/S pin affect BUSY signal behavior in the 70V631S15PRF?

In the 70V631S15PRF, the M/S pin configures BUSY functionality: when M/S = VIH, BUSYL/BUSYR act as outputs indicating port contention; when M/S = VIL, BUSYL/BUSYR become inputs for slave-side arbitration. This enables master/slave cascading without external logic-critical for expanding data bus width beyond 18 bits.

Can the left and right ports of the 70V631S15PRF operate at different I/O voltages?

Yes. OPTL and OPTR are independent; setting OPTL = VIH and OPTR = VIL configures the left port for 3.3 V I/O (requiring VDDQL = 3.3 V) and the right port for 2.5 V I/O (requiring VDDQR = 2.5 V). This allows seamless interfacing with mixed-voltage SoCs or FPGAs without level shifters.

What is the purpose of the semaphore function in the 70V631S15PRF?

The 70V631S15PRF provides eight hardware semaphore flags accessible via A0–A2. These flags enable atomic read-modify-write operations between ports, allowing lock-free synchronization-for example, coordinating access to shared resources in multi-processor systems without software intervention or race conditions.