Renesas 70T651S10BFG8

Overview

70T651S10BFG8 from IDT (now part of Renesas) is a high-speed 256K × 36-bit asynchronous dual-port static RAM with independent left/right ports, 10 ns read cycle time, 2.5 V core supply, and selectable 2.5 V/3.3 V I/O interface per port-designed for real-time inter-processor communication in telecom switching fabrics and FPGA co-processing systems.

For engineers reviewing the 70T651S10BFG8 datasheet, 70T651S10BFG8 pinout, 70T651S10BFG8 application, or 70T651S10BFG8 equivalent, key selection criteria include simultaneous dual-port access latency, RapidWrite mode timing compliance, M/S arbitration support for cascaded 72-bit+ memory expansion, and industrial-grade thermal stability across –40°C to +85°C.

Technical Context

This device implements true dual-port SRAM cells enabling concurrent read/write to identical addresses without contention. On-chip arbitration logic resolves port conflicts via BUSY flag signaling, while semaphore registers (A0–A2 addressed, I/O0–I/O35 data path) enable inter-processor synchronization without external logic.

Each port features independent CE0/CE1 enables, R/W control, byte-enable lines (BE0–BE3), and OPT-selectable I/O voltage (2.5 V or 3.3 V). JTAG IEEE 1149.1 support enables boundary-scan testing, and ZZ sleep mode reduces standby current to ≤10 mA with full I/O retention except JTAG pins.

Key Specifications

Pinout & Package

208-ball fine-pitch Ball Grid Array (fpBGA), package code BFG208. Body size: 15 mm × 15 mm × 1.4 mm, 0.8 mm ball pitch. All VDD pins require 2.5 V; VDDQ pins must match OPT pin setting (2.5 V if OPT = VSS, 3.3 V if OPT = VDD).

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 70T651S10BFG8 uniquely delivers simultaneous access, hardware semaphore support, and RapidWrite mode - making it the only option for deterministic real-time IPC without added logic or firmware overhead.

Availability

70T651S10BFG8 is available at Aetrix Electronics and suitable for telecom switching fabrics, FPGA co-processing buffers, industrial PLC I/O expansion, and radar signal processing FIFOs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70T651S10BFG8 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 fabless semiconductor company specializing in high-performance timing, memory interface, and RF power solutions for communications and computing infrastructure.

The 70T651S10BFG8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, engineered specifically for deterministic inter-processor communication in telecom, defense, and industrial automation systems demanding sub-10 ns latency and hardware-enforced synchronization.

FAQ

What is the maximum operating frequency supported by the 70T651S10BFG8?

The 70T651S10BFG8 does not operate at a clock frequency-it is an asynchronous SRAM. Its performance is defined by access timing: 10 ns maximum address access time (tAA) and 10 ns read cycle time (tRC). This enables reliable operation with 100 MHz system clocks when interfaced to FPGAs or ASICs with appropriate setup/hold margins, but no internal clock circuitry exists.

Does the 70T651S10BFG8 support true simultaneous read/write to the same memory address?

Yes, the 70T651S10BFG8 implements true dual-port SRAM cells that permit concurrent read and write operations to the exact same memory location. The device resolves potential contention using on-chip arbitration logic and BUSY flag signaling-ensuring data integrity without external intervention or software coordination.

How does RapidWrite mode function in the 70T651S10BFG8, and what design benefit does it provide?

RapidWrite mode in the 70T651S10BFG8 allows consecutive write operations without toggling R/W, CE, or BE signals between cycles-the ending address transition defines the write boundary. This eliminates the need for narrow reset pulses, reduces control logic complexity, and improves sustained write throughput by up to 40% compared to standard asynchronous write sequences.

Can the left and right ports of the 70T651S10BFG8 operate at different I/O voltage levels?

Yes. The 70T651S10BFG8 supports independent I/O voltage selection per port: OPTL sets left-port I/O level (2.5 V or 3.3 V), and OPTR sets right-port level. Corresponding VDDQL and VDDQR supplies must match the OPT setting. This enables direct interfacing with heterogeneous logic families-for example, 2.5 V FPGA fabric and 3.3 V microcontroller peripherals.

What is the role of the M/S pin in 70T651S10BFG8 system-level configurations?

The M/S pin configures the 70T651S10BFG8 as either Master (M/S = VIH) or Slave (M/S = VIL). In Master mode, BUSYx is an output indicating local port contention; in Slave mode, BUSYx is an input reflecting the Master's busy state. This enables daisy-chained memory expansion for >36-bit word widths without external glue logic.