Renesas 70V639S15PRF

Overview

IDT70V639S15PRF from Integrated Device Technology (IDT) is a high-speed, 128K × 18 asynchronous dual-port static RAM with true independent left/right port access, 15 ns maximum read/write cycle time, LVTTL-compatible 3.3 V core supply and selectable 3.3 V/2.5 V I/O supplies per port, and industrial temperature support (–40°C to +85°C). It enables simultaneous read/write to the same memory location in real-time control systems requiring deterministic arbitration.

For engineers reviewing the IDT70V639S15PRF datasheet, IDT70V639S15PRF pinout, IDT70V639S15PRF application, or IDT70V639S15PRF equivalent, key selection criteria include dual-port arbitration latency, BUSY/INT flag timing (tBAA ≤15 ns), M/S master/slave cascading for 36-bit+ bus expansion, and JTAG absence in the 128-pin TQFP package.

Technical Context

The IDT70V639S15PRF implements fully asynchronous dual-port architecture with on-chip hardware semaphore logic, independent CE0/CE1 chip enables per port, and byte-selectable upper/lower data access (UBL/LBL, UBR/LBR). Port arbitration is resolved via dedicated BUSY flags and priority setup time (tAPS = 5 ns), with no external logic required.

It supports mixed-voltage operation: fixed 3.3 V ±150 mV core (VDD), and independently configurable I/O banks (VDDQL/VDDQR) at either 3.3 V ±150 mV or 2.5 V ±100 mV via OPTL/OPTR pins. The device uses true dual-port SRAM cells-not FIFO or register-based-enabling concurrent, collision-free access to identical addresses.

Key Specifications

Pinout & Package

Package: 128-pin Thin Quad Flatpack (PK128), lead-free (green) variant available. All VDD pins require 3.3 V supply; VDDQL/VDDQR must match OPTL/OPTR voltage selection (3.3 V or 2.5 V); all VSS pins grounded.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362AV25 and R1EX24064ASAS, the IDT70V639S15PRF uniquely delivers 15 ns industrial-grade dual-port timing in a 128-pin TQFP with per-port I/O voltage flexibility and integrated hardware arbitration - eliminating external logic and enabling deterministic real-time shared memory.

Availability

IDT70V639S15PRF is available at Aetrix Electronics and suitable for industrial motion control, telecom line card buffering, and avionics data concentrators requiring stable component supply across extended product lifecycles.

Supply support for IDT70V639S15PRF 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 sensor signal conditioning solutions before its acquisition by Renesas Electronics in 2019.

The IDT70V639S product line was engineered for high-reliability, low-latency shared-memory applications in industrial automation, aerospace, and communications infrastructure where deterministic dual-port access and hardware arbitration are mandatory.

FAQ

What is the maximum guaranteed access time for IDT70V639S15PRF across its full industrial temperature range?

The IDT70V639S15PRF is specified with a maximum read cycle time (tRC) of 15 ns and maximum address access time (tAA) of 15 ns over the full –40°C to +85°C industrial temperature range. These values are production-tested and guaranteed, not just characterized, ensuring deterministic timing in harsh environments.

Does IDT70V639S15PRF support JTAG boundary scan, and if not, why?

No, the IDT70V639S15PRF in the 128-pin TQFP (PK128) package does not support JTAG boundary scan. As explicitly stated in the datasheet (page 1, footnote), "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package." JTAG pins (TMS, TCK, TDI, TDO, TRST) are present only in the 208-ball and 256-ball BGA variants.

How does the M/S pin affect BUSY signal behavior in IDT70V639S15PRF?

When M/S = VIH, IDT70V639S15PRF operates as a Master: BUSYL and BUSYR become totem-pole outputs that assert during port contention. When M/S = VIL, it operates as a Slave: BUSYL and BUSYR become inputs used to receive BUSY signals from a Master device in cascaded configurations - enabling hardware flow control without software polling.

Can both ports of IDT70V639S15PRF operate at different I/O voltages simultaneously?

Yes. The IDT70V639S15PRF supports independent I/O voltage selection per port: OPTL sets VDDQL to 3.3 V (VIH) or 2.5 V (VIL), and OPTR sets VDDQR identically but separately. This allows left port to interface with 2.5 V logic while right port connects to 3.3 V controllers - confirmed in Pin Names table (page 5) and DC Operating Conditions (pages 7–8).

What is the purpose of the semaphore function in IDT70V639S15PRF, and how is it accessed?

The semaphore function in IDT70V639S15PRF provides eight hardware flags for inter-port synchronization. Accessed via A0–A2 address lines with SEM = VIL and CE = VIH (Truth Table II, page 6), it allows one port to set and both ports to read flags atomically - eliminating race conditions in resource sharing without CPU intervention or external latches.