Renesas 70V658S12BC8

Overview

70V658S12BC8 from IDT is a high-speed 64K × 36 asynchronous dual-port static RAM with true independent left/right ports, 12 ns maximum access time (commercial/industrial), LVTTL-compatible 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port-used in real-time DSP co-processing, FPGA memory bridging, and redundant control systems requiring simultaneous read/write to shared memory.

For engineers reviewing the 70V658S12BC8 datasheet, 70V658S12BC8 pinout, 70V658S12BC8 application, or 70V658S12BC8 equivalent, this page delivers verified functional architecture, port arbitration timing, byte-enable granularity, JTAG 1149.1 compliance, and industrial-grade thermal performance for deterministic dual-port memory integration.

Technical Context

The 70V658S12BC8 implements fully asynchronous dual-port operation with separate address, control, and 36-bit bidirectional I/O buses per port-enabling concurrent access to any memory location without internal synchronization overhead. It integrates on-chip semaphore logic, BUSY/INT flags, and Master/Slave arbitration for multi-processor memory coordination.

Each port supports independent power management via dual chip enables (CE0/CE1), per-port OPT-selectable I/O voltage (3.3 V or 2.5 V), and byte-level write enable (BE0–BE3) for 9-bit sub-word writes. The device uses true dual-port SRAM cells-not FIFO or register-based emulation-and complies with IEEE 1149.1 JTAG boundary-scan for testability.

Key Specifications

Pinout & Package

208-pin Plastic Quad Flatpack (PQFP), 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 OPTL/OPTR voltage selection (3.3 V or 2.5 V); 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 CY7C1362BV33-12BGXI, the 70V658S12BC8 offers per-port I/O voltage selection and PQFP packaging for easier prototyping and mixed-voltage integration; compared with IDT70V659S12BC8, it delivers optimal cost-performance balance for 64K-depth applications without over-provisioning memory.

Availability

70V658S12BC8 is available at Aetrix Electronics and suitable for real-time DSP co-processing, FPGA-to-processor memory bridging, and redundant control systems requiring stable component supply across extended product lifecycles.

Supply support for 70V658S12BC8 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 interface, and RF solutions for communications, computing, and industrial markets.

The IDT70V658S12BC8 belongs to the 70V65x family of asynchronous dual-port SRAMs designed specifically for deterministic, low-latency memory sharing between heterogeneous processors in mission-critical embedded systems.

FAQ

What is the memory organization and address mapping for the 70V658S12BC8?

The 70V658S12BC8 implements a 64K × 36-bit memory array, meaning it contains 65,536 words of 36 bits each. Address lines A0L–A15L and A0R–A15R are active; A16L and A16R are No Connect pins for this variant. This yields a total capacity of 2.25 Mbit with full left/right port independence and simultaneous access capability.

Does the 70V658S12BC8 support mixed-voltage operation between its two ports?

Yes, the 70V658S12BC8 supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL to VDD configures the left port for 3.3 V I/O levels (with VDDQL = 3.3 V), while setting OPTR to VSS configures the right port for 2.5 V I/O levels (with VDDQR = 2.5 V). This enables direct interfacing with mismatched voltage-domain processors without level shifters.

How does the BUSY signal function in Master/Slave configurations of the 70V658S12BC8?

In Master mode (M/S = VIH), BUSYL/BUSYR are totem-pole outputs that assert HIGH when the opposite port initiates a write to an address currently being read - blocking conflicting accesses. In Slave mode (M/S = VIL), BUSYL/BUSYR become inputs used to detect contention from the Master. The 70V658S12BC8 guarantees tBDD ≤ 12 ns for valid data after BUSY deassertion in Master mode.

What is the role of the semaphore logic in the 70V658S12BC8, and how is it accessed?

The 70V658S12BC8 includes eight hardware semaphore flags accessible via addresses A0–A2 and data lines I/O0–I/O35. To access semaphores, CE must be HIGH and SEM must be LOW - distinct from normal RAM access (CE LOW, SEM HIGH). The semaphore logic enables atomic test-and-set operations between ports, eliminating software locks and reducing inter-processor synchronization latency to ≤8 ns.

Is the 70V658S12BC8 pin-compatible with other members of the IDT70V65x family?

Yes, the 70V658S12BC8 shares identical pinout, package (208-pin PQFP), and signal definitions with IDT70V657S12BC8 (32K × 36) and IDT70V659S12BC8 (128K × 36). All three support the same voltage options, timing specs, and feature set - enabling seamless density scaling within the same PCB layout and firmware framework.