Renesas 70V639S10PRF

Overview

IDT70V639S10PRF from Integrated Device Technology is a high-speed 128K × 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 OPTL/OPTR pins. It enables simultaneous access to the same memory location in systems requiring real-time inter-processor communication, such as telecom line cards and industrial motion controllers.

For engineers reviewing the IDT70V639S10PRF datasheet, IDT70V639S10PRF pinout, IDT70V639S10PRF application, or IDT70V639S10PRF equivalent, key selection criteria include true dual-port arbitration logic, M/S-selectable BUSY flag behavior, on-chip semaphore support for resource locking, and compatibility with 128-pin TQFP layouts requiring no external glue logic for depth expansion.

Technical Context

The IDT70V639S10PRF implements true dual-port SRAM cells with separate address, control, and bidirectional I/O buses for left (L) and right (R) ports - enabling concurrent read/write operations without contention. Its on-chip arbitration logic resolves port conflicts using BUSY signaling, with M/S pin determining whether BUSY acts as output (Master) or input (Slave).

Each port supports independent I/O voltage selection (3.3 V or 2.5 V) via dedicated OPTL/OPTR pins and corresponding VDDQL/VDDQR supplies. Semaphore and interrupt flags (SEML/SEMR, INTL/INTR) are implemented in hardware with dedicated address-mapped registers (A0–A2), and JTAG boundary-scan is omitted in the PK128 package due to pin count constraints.

Key Specifications

Pinout & Package

Package: 128-pin Thin Quad Flatpack (PK128), 14 mm × 20 mm × 1.4 mm body, 0.5 mm lead pitch, lead-free (green) finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1365KV18 and R1EX24016AS, the IDT70V639S10PRF uniquely delivers true asynchronous dual-port operation with per-port voltage flexibility, on-chip semaphore, and configurable BUSY arbitration - making it optimal for deterministic real-time embedded inter-processor communication where timing predictability and hardware resource locking are critical.

Availability

IDT70V639S10PRF is available at Aetrix Electronics and suitable for telecom infrastructure, industrial motion control, automotive ADAS, and medical imaging systems requiring stable component supply, long-lifecycle support, and guaranteed pinout consistency across production batches.

Supply support for IDT70V639S10PRF 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 power management ICs for communications, computing, and industrial markets.

The IDT70V639S product line was designed specifically for high-reliability, low-latency inter-processor communication in real-time embedded systems - emphasizing deterministic arbitration, flexible voltage interfacing, and hardware-accelerated resource synchronization.

FAQ

What is the maximum operating frequency supported by the IDT70V639S10PRF?

The IDT70V639S10PRF does not operate on a clock signal - it is an asynchronous dual-port SRAM. Its performance is specified by access time: 10 ns maximum read cycle time (tRC) and address access time (tAA) under commercial conditions (0°C to +70°C). This translates to effective throughput exceeding 100 million words per second per port without clock domain constraints.

How does the M/S pin affect BUSY flag behavior in the IDT70V639S10PRF?

In the IDT70V639S10PRF, the M/S pin configures BUSY functionality: when M/S = VIH, BUSYL/BUSYR act as totem-pole outputs indicating port contention (Master mode); when M/S = VIL, BUSYL/BUSYR become inputs used to stall the local port during arbitration (Slave mode). This enables hierarchical master/slave memory configurations without external logic.

Can both ports of the IDT70V639S10PRF operate at different I/O voltages simultaneously?

Yes. The IDT70V639S10PRF 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 - enabling direct interfacing with mixed-voltage processors (e.g., 3.3 V DSP + 2.5 V FPGA) without level shifters.

What is the function of the semaphore feature in the IDT70V639S10PRF, and how is it accessed?

The IDT70V639S10PRF integrates eight hardware semaphore flags accessible via addresses A0–A2 (000–111). To use them, SEM must be asserted low while CE is high (per Truth Table II). Semaphore reads return the flag state on all I/O lines; writes load I/O0 into the selected flag. This provides atomic resource-locking capability without software polling or external mutex hardware.

Is JTAG boundary-scan supported on the IDT70V639S10PRF in its 128-pin TQFP package?

No. JTAG (IEEE 1149.1) is explicitly unsupported on the IDT70V639S10PRF in the 128-pin TQFP (PK128) package due to insufficient pin count - as confirmed in the datasheet note on page 1: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package." JTAG pins (TCK, TMS, TDI, TDO, TRST) are present only in the 208-ball and 256-ball BGA variants.