Renesas 70V658S10BCG

Overview

70V658S10BCG from IDT is a high-speed 64K × 36 asynchronous dual-port static RAM with true independent left/right ports, 10 ns max access time (commercial grade), LVTTL-compatible I/Os, and on-chip semaphore arbitration logic. It supports selectable 3.3 V or 2.5 V I/O voltage per port via OPTL/OPTR pins and operates across –40°C to +85°C industrial temperature range. Used in real-time inter-processor communication buffers and FPGA co-processor memory interfaces.

For engineers reviewing the 70V658S10BCG datasheet, 70V658S10BCG pinout, 70V658S10BCG application, or 70V658S10BCG equivalent, this page delivers verified specifications, validated pin functions, confirmed dual-port arbitration behavior, and real-world use cases for embedded multiprocessing systems requiring deterministic, contention-free shared memory access.

Technical Context

The 70V658S10BCG implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses for left (L) and right (R) ports - enabling simultaneous read/write to the same memory location without external arbitration logic. Its on-chip semaphore logic supports eight hardware flags accessible via A0–A2, with dedicated SEM/INT/BUSY signals per port.

Each port features independent chip enables (CE0/CE1), byte enables (BE0–BE3 for 9-bit bytes), read/write (R/W), output enable (OE), and master/slave select (M/S). The device uses internal power-down control triggered by CE asserts and supports JTAG IEEE 1149.1 boundary scan via TDI/TDO/TCK/TMS/TRST pins.

Key Specifications

Pinout & Package

70V658S10BCG is packaged in a 256-ball fine-pitch Ball Grid Array (BCG256), body size ≈ 17 mm × 17 mm × 1.4 mm, 1.0 mm ball pitch. All VDD pins require 3.3 V supply; VDDQL/VDDQR must match OPTL/OPTR selection (3.3 V or 2.5 V); 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 and 23K640, the 70V658S10BCG uniquely delivers per-port I/O voltage flexibility, integrated JTAG, and hardware semaphore - making it the only option among the three that supports deterministic, mixed-voltage, multi-processor shared memory without external logic.

Availability

70V658S10BCG is available at Aetrix Electronics and suitable for real-time DSP co-processor buffers, FPGA-to-MCU shared memory interfaces, and telecom line card packet buffers requiring stable component supply, long-term lifecycle assurance, and industrial-grade thermal performance.

Supply support for 70V658S10BCG 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), now part of Renesas Electronics, is a semiconductor company specializing in timing, memory interface, RF, and high-performance interconnect solutions for communications, computing, and industrial markets.

The IDT70V658 belongs to the 70V659/58/57 family of high-speed asynchronous dual-port SRAMs designed specifically for deterministic, low-latency inter-processor communication in embedded multiprocessing systems.

FAQ

What is the memory organization and address space of the 70V658S10BCG?

The 70V658S10BCG implements a 64K × 36-bit memory array, totaling 2.25 Mbit. Its effective address space spans A0–A15 (16 address lines), as A16L and A16R are No Connect (NC) per datasheet Note 1. This configuration supports direct mapping to 64K-word systems without address decoding overhead. The 70V658S10BCG does not support 128K or 32K variants - those correspond to 70V659 and 70V657 respectively within the same family.

How does the M/S pin affect BUSY functionality in the 70V658S10BCG?

In the 70V658S10BCG, the M/S pin configures BUSY behavior: when M/S = VIH, the device operates as MASTER and BUSYL/BUSYR are push-pull outputs indicating port contention; when M/S = VIL, it operates as SLAVE and BUSYL/BUSYR become inputs used to stall writes on the local port. This dual-mode design enables hierarchical arbitration in cascaded configurations - for example, one 70V658S10BCG as MASTER coordinating multiple SLAVE devices in a 72-bit+ memory system.

Can the left and right ports of the 70V658S10BCG operate at different I/O voltages?

Yes - the 70V658S10BCG supports independent I/O voltage selection per port via OPTL and OPTR. Setting OPTL = VDD (3.3 V) and OPTR = VSS (0 V) configures the left port for 3.3 V LVTTL signaling and the right port for 2.5 V operation. Corresponding VDDQL and VDDQR supplies must match these selections. This capability eliminates external level shifters when interfacing with heterogeneous processors - for instance, an FPGA I/O bank at 2.5 V and an ARM microcontroller at 3.3 V.

What is the role of the semaphore logic in the 70V658S10BCG, and how is it accessed?

The 70V658S10BCG integrates eight hardware semaphore flags accessible via I/O0–I/O7 when SEMX = VIL and CEX = VIH (per Truth Table II). Address lines A0–A2 select the flag; writes place data from I/O0 into the selected flag, reads return the flag value across all 36 I/O lines. This dedicated hardware replaces software-based spinlocks, reducing inter-processor synchronization latency to ≤8 ns (tSOP), and is essential for real-time OS task coordination and resource allocation.

Does the 70V658S10BCG support JTAG boundary scan, and what pins are required?

Yes - the 70V658S10BCG fully complies with IEEE 1149.1 JTAG boundary scan. Required pins are TDI (Test Data In), TDO (Test Data Out), TCK (Test Clock, 10 MHz max), TMS (Test Mode Select), and TRST (Test Reset). These signals are dedicated and do not share with functional I/Os. JTAG enables full-pin visibility for PCB assembly validation and in-system test of BGA solder joints - critical for high-reliability industrial and aerospace applications where 70V658S10BCG is commonly deployed.