Renesas 70V639S10PRFG8

Overview

70V639S10PRFG8 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 real-time inter-processor communication systems.

For engineers reviewing the 70V639S10PRFG8 datasheet, 70V639S10PRFG8 pinout, 70V639S10PRFG8 application, or 70V639S10PRFG8 equivalent, this device supports true dual-port arbitration, on-chip semaphore logic, BUSY/INT flag signaling, and Master/Slave cascading for 36-bit+ memory expansion - critical for embedded control, telecom switching, and FPGA co-processor buffering.

Technical Context

The 70V639S10PRFG8 implements true dual-port SRAM cells with separate address, data, and control buses per port, enabling fully asynchronous, concurrent read/write operations without external arbitration logic. Its on-chip arbitration engine resolves port contention using address-match and chip-enable priority schemes, with programmable BUSY assertion timing (tBAA ≤ 10 ns) and configurable M/S mode.

Each port supports independent I/O voltage selection (3.3 V or 2.5 V) via dedicated OPT pins and corresponding VDDQ supplies, while the core VDD remains fixed at 3.3 V ±150 mV. JTAG boundary-scan (IEEE 1149.1) is implemented but excluded on the 128-pin TQFP package - confirmed by datasheet note on PK128.

Key Specifications

Pinout & Package

70V639S10PRFG8 is housed in a 128-pin Thin Quad Flatpack (PK128) package. Pin functions are asymmetrically distributed across left (L) and right (R) ports, with dedicated control, address, data, and arbitration signals per side. All VDD pins require 3.3 V; VDDQL/VDDQR must match OPTL/OPTR logic level (VIH → 3.3 V, VIL → 2.5 V).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-10ZXC and R1EX24016AS0C-10#U0, the 70V639S10PRFG8 uniquely delivers 18-bit width, per-port I/O voltage selection, hardware semaphore, and Master/Slave cascading - reducing BOM count and eliminating timing-critical external arbitration design effort.

Availability

70V639S10PRFG8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and avionics applications requiring stable component supply, long-lifecycle support, and guaranteed commercial-grade performance.

Supply support for 70V639S10PRFG8 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 for high-reliability, low-latency inter-processor communication in real-time embedded systems - emphasizing deterministic arbitration, flexible voltage interfacing, and seamless memory expansion.

FAQ

What is the maximum operating frequency supported by the 70V639S10PRFG8?

The 70V639S10PRFG8 does not operate on a clock signal - it is an asynchronous dual-port SRAM. Its speed is defined by access timing parameters: tRC (read cycle time) and tWC (write cycle time) are both rated at 10 ns maximum for the commercial-grade 70V639S10PRFG8. This enables effective interfacing with systems running up to 100 MHz with appropriate setup/hold margins, but no internal clock governs operation.

Does the 70V639S10PRFG8 support JTAG boundary-scan testing?

The 70V639S10PRFG8 implements IEEE 1149.1 JTAG functionality in its design, but JTAG is explicitly disabled on the 128-pin TQFP package (PK128) due to pin count limitations, as stated in the datasheet note on page 1. JTAG is available only on the 208-ball and 256-ball BGA variants (e.g., 70V639BF/BC). Therefore, the 70V639S10PRFG8 does not support JTAG test access.

How is the BUSY signal used in Master vs. Slave configuration of the 70V639S10PRFG8?

In Master mode (M/S = VIH), BUSYL/BUSYR are outputs that assert when port contention occurs - e.g., simultaneous writes to the same address. In Slave mode (M/S = VIL), BUSYL/BUSYR become inputs; the external Master drives them to block writes during conflict. The 70V639S10PRFG8's BUSY behavior is strictly mode-dependent and non-tri-state (totem-pole), as confirmed in datasheet Note 2 on page 2.

Can the left and right ports of the 70V639S10PRFG8 operate at different I/O voltages?

Yes - the 70V639S10PRFG8 supports independent I/O voltage selection per port. OPTL sets left-port I/O voltage (3.3 V if VIH, 2.5 V if VIL); OPTR sets right-port I/O voltage identically. Corresponding VDDQL and VDDQR supplies must match those levels. This capability is documented in Pin Names table (page 5) and DC Operating Conditions (pages 7–8) of the datasheet.

What is the purpose of the semaphore function in the 70V639S10PRFG8, and how is it accessed?

The 70V639S10PRFG8 includes eight hardware semaphore flags used for inter-processor synchronization. They reside in a dedicated address space (A0–A2) and are accessed when CE = VIH and SEM = VIL - distinct from normal RAM access (CE = VIL, SEM = VIH). Semaphore read/write timing (tSAA ≤ 10 ns, tSOP ≤ 4 ns) is specified separately in AC tables, confirming deterministic, low-overhead flag management without software polling.