Renesas 70V659S10DR

Overview

70V659S10DR from IDT is a high-speed 128K × 36-bit asynchronous 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-designed for real-time inter-processor communication in telecom line cards and industrial motion controllers.

For engineers reviewing the 70V659S10DR datasheet, 70V659S10DR pinout, 70V659S10DR application, or 70V659S10DR equivalent, key selection criteria include true dual-port arbitration, on-chip semaphore logic, JTAG 1149.1 compliance, and support for MASTER/SLAVE cascading to expand data width beyond 36 bits without external logic.

Technical Context

This device implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port (36-bit left + 36-bit right), enabling simultaneous read/write access to the same memory location. Port arbitration is handled by on-chip logic with BUSY flag signaling and semaphore registers accessible via A0–A2.

Each port supports independent power management via dual chip enables (CE0/CE1), byte-enable masking (BE0–BE3), and configurable I/O voltage (3.3 V or 2.5 V) controlled by OPTL/OPTR pins. JTAG boundary-scan testing is supported through TDI/TDO/TCK/TMS/TRST pins compliant with IEEE 1149.1.

Key Specifications

Pinout & Package

208-pin PQFP package (DR208/DRG208), 28 mm × 28 mm × 3.5 mm body, 0.5 mm lead pitch. All VDD pins require 3.3 V connection; VDDQL/VDDQR must match selected I/O voltage (3.3 V or 2.5 V) per port; all VSS pins tied 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 AS7C3256B-10JIN, the 70V659S10DR uniquely delivers per-port I/O voltage selection, integrated semaphore registers, and IEEE 1149.1 JTAG-enabling robust, testable, mixed-voltage dual-processor designs without external glue logic.

Availability

70V659S10DR is available at Aetrix Electronics and suitable for telecom infrastructure, industrial motion control, avionics data concentrators, and medical imaging systems requiring stable component supply across extended product lifecycles.

Supply support for 70V659S10DR 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) is a fabless semiconductor company specializing in high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The 70V659S10DR belongs to IDT's high-speed asynchronous dual-port SRAM product line, engineered specifically for deterministic, low-latency inter-processor communication in real-time embedded systems.

FAQ

What is the maximum operating frequency supported by the 70V659S10DR?

The 70V659S10DR does not operate on a clock signal-it is an asynchronous device. Its performance is defined by access times: 10 ns maximum read cycle time (tRC), 10 ns address access time (tAA), and 10 ns chip enable access time (tACE). These values guarantee deterministic latency without clock domain constraints, making it ideal for systems requiring precise timing control between heterogeneous processors.

How does the MASTER/SLAVE (M/S) pin affect BUSY flag behavior in the 70V659S10DR?

When M/S = VIH, the 70V659S10DR configures as MASTER and drives BUSYL/BUSYR as totem-pole outputs indicating port contention. When M/S = VIL, it configures as SLAVE and accepts BUSYL/BUSYR as inputs to inhibit writes during arbitration. This hardware-controlled mode eliminates software polling and ensures atomic semaphore operations across both ports.

Can the left and right ports of the 70V659S10DR operate at different I/O voltages simultaneously?

Yes-the 70V659S10DR supports independent I/O voltage selection per port. OPTL sets left-port I/O voltage (3.3 V if tied to VDD, 2.5 V if tied to VSS), and OPTR does the same for the right port. Corresponding VDDQL and VDDQR supplies must match the selected voltage. This enables direct interfacing with mixed-voltage subsystems-for example, 3.3 V FPGA and 2.5 V ASIC-without external level shifters.

Does the 70V659S10DR support JTAG boundary-scan testing, and what pins are required?

Yes, the 70V659S10DR fully complies with IEEE 1149.1 JTAG. Required pins are TDI (Test Data In), TDO (Test Data Out), TCK (Test Clock, ≤10 MHz), TMS (Test Mode Select), and TRST (Test Reset). These pins enable production-level boundary-scan testing of PCB interconnects and provide visibility into internal SRAM and control logic during debug-reducing test development time and improving yield.

What is the function of the semaphore registers in the 70V659S10DR, and how are they accessed?

The 70V659S10DR includes eight hardware semaphore flags accessible via I/O0–I/O35 using address lines A0–A2. To access them, SEM = VIL and CE = VIH (opposite of normal RAM access). Each flag can be written by one port and read by either port, enabling lock-free resource sharing between processors. This eliminates software-based spinlocks and reduces inter-processor latency to under 10 ns for flag updates.