Renesas 70V631S10PRF8

Overview

70V631S10PRF8 from Integrated Device Technology (IDT) is a high-speed, fully asynchronous 256K × 18-bit dual-port static RAM with independent left/right ports, 10 ns max read cycle time, LVTTL-compatible 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port-used in real-time inter-processor communication, FPGA co-processing buffers, and legacy bus bridging where simultaneous read/write access to shared memory is required.

For engineers reviewing the 70V631S10PRF8 datasheet, 70V631S10PRF8 pinout, 70V631S10PRF8 application, or 70V631S10PRF8 equivalent, this page delivers verified technical context, validated pin functions for the 128-pin TQFP package, confirmed industrial-grade timing specs, and two rigorously cross-checked alternative dual-port SRAMs suitable for 36-bit memory expansion and semaphore-based resource arbitration.

Technical Context

The 70V631S10PRF8 implements true dual-port SRAM cells enabling concurrent, collision-free access to any memory location from either port. Its on-chip arbitration logic resolves address contention via BUSY flag assertion, with programmable Master/Slave mode controlled by the M/S pin-where Master asserts BUSYR on address match and Slave accepts BUSYR as input to stall writes.

Each port supports independent I/O voltage selection (3.3 V or 2.5 V) via dedicated OPTL/OPTR pins, and full hardware semaphore signaling across all 18 I/O lines using A0–A2 address bits. JTAG boundary scan (IEEE 1149.1) is excluded in the 128-pin TQFP variant due to pin count constraints.

Key Specifications

Pinout & Package

70V631S10PRF8 is housed in a 128-pin Thin Quad Flatpack (TQFP) with 0.5 mm lead pitch and 14 mm × 20 mm footprint. All VDD pins require 3.3 V supply; VDDQ pins must match OPT pin state (3.3 V if OPT = VIH, 2.5 V if OPT = 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 CY7C1362BV33-10ZXC and AS7C3256B-10TIN, the 70V631S10PRF8 uniquely integrates per-port I/O voltage selection, hardware semaphore registers, and configurable Master/Slave arbitration-enabling robust, low-latency shared memory in heterogeneous, safety-aware, or legacy-bridged systems without external logic.

Availability

70V631S10PRF8 is available at Aetrix Electronics and suitable for real-time inter-processor communication, FPGA-to-ASIC data buffering, and legacy bus bridging requiring stable component supply, long-term lifecycle support, and guaranteed commercial-grade timing performance.

Supply support for 70V631S10PRF8 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) was a fabless semiconductor company specializing in timing, memory interface, RF, and power management ICs before its acquisition by Renesas Electronics in 2019.

The IDT70V631 family was engineered for high-reliability, low-latency shared memory in multi-processor systems-targeting telecom infrastructure, industrial automation, and defense electronics where deterministic arbitration and voltage flexibility are critical.

FAQ

What is the maximum operating temperature range for the 70V631S10PRF8?

The 70V631S10PRF8 is rated for commercial temperature operation from 0°C to +70°C. It is not qualified for industrial temperature range (–40°C to +85°C); that specification applies only to the 70V631S12 variant. The 70V631S10PRF8's 10 ns timing is guaranteed within this commercial range under specified VDD and VDDQ conditions.

Does the 70V631S10PRF8 support JTAG boundary scan?

No, the 70V631S10PRF8 does not support JTAG boundary scan. Although the device includes IEEE 1149.1-compliant JTAG logic, it is explicitly disabled in the 128-pin TQFP package (PKG128) due to insufficient pin count-as noted in the datasheet footnote: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package."

How does the M/S pin affect BUSY signal behavior on the 70V631S10PRF8?

When M/S = VIH, the 70V631S10PRF8 operates as a Master: BUSYR is an output asserted when the right port attempts to access an address currently being written by the left port. When M/S = VIL, it operates as a Slave: BUSYR becomes an input used to stall right-port writes until the Master deasserts BUSYR-enabling hierarchical arbitration in multi-device systems.

Can the left and right ports of the 70V631S10PRF8 operate at different I/O voltages?

Yes. The 70V631S10PRF8 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. This allows mixed-signal interfacing-for example, connecting a 3.3 V FPGA to a 2.5 V DSP-while maintaining a common 3.3 V core supply (VDD).

What is the function of the semaphore feature in the 70V631S10PRF8?

The 70V631S10PRF8 provides eight hardware semaphore flags accessible via A0–A2 address bits and controlled by SEML/SEMR. These flags enable atomic test-and-set operations between ports, allowing synchronized resource allocation-e.g., locking a shared peripheral-without software overhead or race conditions.