Renesas 70V658S12BFI

Overview

70V658S12BFI from IDT is a high-speed 64K × 36 asynchronous dual-port static RAM with independent left/right ports, 12 ns maximum access time (commercial grade), LVTTL-compatible 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port via OPT pins. It enables simultaneous read/write to the same memory location in real-time communication buffers and FPGA co-processor interfaces.

For engineers reviewing the 70V658S12BFI datasheet, 70V658S12BFI pinout, 70V658S12BFI application, or 70V658S12BFI equivalent, this page delivers verified technical context, pin-level design meaning, true dual-port arbitration behavior, JTAG-compliant test support, and industrial-grade thermal reliability - all validated against IDT's official 70V659/58/57S specification.

Technical Context

This device implements fully asynchronous dual-port architecture with on-chip semaphore logic, independent CE0/CE1 and BE0–BE3 controls per port, and master/slave arbitration using M/S pin configuration. BUSY flags operate as non-tri-state totem-pole outputs for deterministic contention resolution.

Each port supports separate power domains: fixed 3.3 V ±150 mV for VDD (core), and independently configurable 3.3 V or 2.5 V for VDDQx and control signals via OPTL/OPTR. A16 is NC for 70V658S12BFI, confirming its 64K × 36 (2.3 Mbit) density - distinct from 128K × 36 (70V659) and 32K × 36 (70V657) variants.

Key Specifications

Pinout & Package

70V658S12BFI is packaged in a 208-pin Plastic Quad Flatpack (PQFP), body size ≈28 mm × 28 mm × 3.5 mm, with 0.5 mm lead pitch. All VDD pins require 3.3 V connection; VDDQL/VDDQR must match OPTL/OPTR logic state (3.3 V if OPT = VIH, 2.5 V if OPT = VIL); all VSS pins connect 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 and AS7C362000B-12TIN, the 70V658S12BFI uniquely delivers per-port 3.3 V/2.5 V I/O configurability, integrated semaphore logic, and IEEE 1149.1 JTAG - enabling lower BOM count, reduced firmware complexity, and higher production test coverage in demanding embedded systems.

Availability

70V658S12BFI is available at Aetrix Electronics and suitable for telecom line card buffers, FPGA co-processor memory, and motor drive controllers requiring stable component supply across extended product lifecycles.

Supply support for 70V658S12BFI 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 timing, memory interface, and RF solutions, now part of Renesas Electronics since 2019.

The 70V659/58/57 family was designed for high-reliability, low-latency inter-processor communication in networking, industrial automation, and medical imaging - emphasizing hardware arbitration, mixed-voltage compatibility, and JTAG testability.

FAQ

What is the exact memory density and organization of the 70V658S12BFI?

The 70V658S12BFI is a 64K × 36 asynchronous dual-port SRAM, totaling 2.304 Mbit. Its address space uses A0–A15 (16 bits), with A16 designated as No Connect - distinguishing it from the 128K × 36 (70V659) and 32K × 36 (70V657) variants in the same family. This confirmed 64K depth is critical for accurate address decoding and memory mapping in target systems.

Does the 70V658S12BFI support both 3.3 V and 2.5 V I/O interfaces simultaneously?

Yes - the 70V658S12BFI supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL = VIH configures the left port for 3.3 V I/O (requiring VDDQL = 3.3 V), while OPTR = VIL configures the right port for 2.5 V I/O (requiring VDDQR = 2.5 V). This enables direct interfacing with mixed-voltage SoCs and FPGAs without external level shifters.

How does the BUSY flag function in master versus slave configuration on the 70V658S12BFI?

When M/S = VIH, the 70V658S12BFI operates as Master and asserts BUSYL/BUSYR as active-high totem-pole outputs during port contention. When M/S = VIL, it operates as Slave and accepts BUSYL/BUSYR as active-high inputs - allowing hierarchical arbitration across multiple devices. Both configurations use non-tri-state outputs/inputs, eliminating need for external pull-ups or bus keepers.

What is the role of the semaphore logic in the 70V658S12BFI, and how is it accessed?

The 70V658S12BFI includes on-chip semaphore logic for eight shared flags, addressed via A0–A2 and written to I/O0/read from all I/O lines (I/O0–I/O35). Access occurs when CE = VIH and SEM = VIL - a dedicated control mode separate from main memory access (which uses CE = VIL and SEM = VIH). This hardware implementation eliminates software polling delays and race conditions in multi-processor synchronization.

Is JTAG boundary-scan supported on the 70V658S12BFI, and what are the key constraints?

Yes - the 70V658S12BFI implements full IEEE 1149.1 JTAG compliance with TMS, TCK (≤10 MHz), TDI, TDO, and TRST pins. All JTAG signals are LVTTL-compatible and require VDD = 3.3 V. The TAP controller is functional across the full industrial temperature range, enabling production test and in-system verification without additional debug infrastructure.