Renesas 70V631S10PRFG8

Overview

70V631S10PRFG8 from IDT (now Renesas) is a high-speed 256K × 18 asynchronous dual-port static RAM with fully independent left/right ports, 10 ns max read cycle 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 access to the same memory location in real-time systems such as telecom line cards and industrial motion controllers.

For engineers reviewing the 70V631S10PRFG8 datasheet, 70V631S10PRFG8 pinout, 70V631S10PRFG8 application, or 70V631S10PRFG8 equivalent, key selection criteria include true dual-port arbitration logic, BUSY/INT semaphore signaling, JTAG support (excluded in TQFP but present in BGA packages), and 128-pin TQFP package compatibility for space-constrained PCB layouts.

Technical Context

The 70V631S10PRFG8 implements full on-chip hardware semaphore signaling between ports using dedicated SEM/INT/BUSY pins, enabling deterministic resource sharing without external logic. Its port arbitration logic resolves contention via address-match or chip-enable priority, with configurable M/S (Master/Slave) mode for cascaded 36-bit+ memory expansion.

Each port supports independent power domains: fixed 3.3 V ±150 mV core (VDD) and user-selectable 3.3 V ±150 mV or 2.5 V ±100 mV I/O supplies (VDDQL/VDDQR) controlled by OPTL/OPTR. The device operates across commercial (0°C to +70°C) temperature range and delivers 10 ns max tRC, tAA, and tACE timing at 3.3 V.

Key Specifications

Pinout & Package

70V631S10PRFG8 is housed in a 128-pin Thin Quad Flatpack (TQFP) package (PKG128), measuring approximately 14 mm × 20 mm × 1.4 mm. All VDD pins require connection to 3.3 V; VDDQL/VDDQR must match OPTL/OPTR logic levels (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 CY7C1362BV33-10BGXI and AS7C3256PFSIG, the 70V631S10PRFG8 uniquely combines 10 ns performance, per-port 2.5 V/3.3 V I/O flexibility, and integrated hardware arbitration - making it optimal for mixed-voltage, multi-processor designs where PCB real estate and deterministic latency are critical.

Availability

70V631S10PRFG8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial motion control, automated test equipment, and avionics data buffering requiring stable component supply and long-term manufacturing continuity.

Supply support for 70V631S10PRFG8 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 semiconductor company specializing in timing, memory interface, and RF solutions for high-performance computing and communications systems.

The 70V631S10PRFG8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for real-time, multi-processor systems requiring deterministic memory access and hardware-based inter-processor synchronization.

FAQ

What is the maximum operating frequency supported by the 70V631S10PRFG8?

The 70V631S10PRFG8 does not operate at a fixed clock frequency; it is an asynchronous device. Its maximum effective throughput is determined by its 10 ns read cycle time (tRC), enabling reliable operation with bus cycles as short as 10 ns - equivalent to a sustained 100 MHz data rate under ideal conditions. Timing margins must be verified against actual system setup/hold requirements and signal integrity.

Does the 70V631S10PRFG8 support JTAG boundary scan?

No, the 70V631S10PRFG8 in the 128-pin TQFP package (PKG128) does not support JTAG boundary scan, as explicitly stated in the datasheet: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package." JTAG is only available on the 208-ball and 256-ball BGA variants (BF208/BC256).

How does the BUSY signal function in Master vs Slave configuration for the 70V631S10PRFG8?

In Master mode (M/S = VIH), BUSYL/BUSYR is an output that asserts when the opposite port attempts access to the same address - blocking further writes until cleared. In Slave mode (M/S = VIL), BUSYL/BUSYR becomes an input; the device monitors this signal to inhibit its own write operations during contention. This dual-role design enables flexible arbitration topologies without external logic.

Can both ports of the 70V631S10PRFG8 operate at different I/O voltages simultaneously?

Yes. The 70V631S10PRFG8 supports independent I/O voltage selection per port: OPTL sets left-port I/O voltage (3.3 V or 2.5 V), and OPTR sets right-port I/O voltage. Corresponding VDDQL and VDDQR supplies must be configured accordingly - e.g., VDDQL = 2.5 V and VDDQR = 3.3 V - enabling direct interfacing with mixed-voltage FPGAs or ASICs.

What is the purpose of the semaphore feature in the 70V631S10PRFG8, and how is it accessed?

The 70V631S10PRFG8 includes eight hardware semaphore flags used for inter-processor synchronization. They are accessed by asserting SEM = VIL and CE = VIH while addressing A0–A2 (0–7); I/O0 writes the flag value, and all I/O pins (I/O0–I/O17) read it back. This eliminates software polling and ensures atomic, lock-free coordination between ports - critical for real-time determinism.