Renesas 70T651S10BF8

Overview

70T651S10BF8 from Integrated Device Technology 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-used in real-time inter-processor communication, FPGA co-processor buffering, and telecom line card memory arbitration.

For engineers reviewing the 70T651S10BF8 datasheet, 70T651S10BF8 pinout, 70T651S10BF8 application, or 70T651S10BF8 equivalent, key selection criteria include dual-port arbitration logic, RapidWrite mode timing, M/S master/slave cascading capability, and industrial-grade –40°C to +85°C operation in BF-208 fpBGA package.

Technical Context

This device implements true dual-port SRAM architecture with fully asynchronous access on both ports, on-chip semaphore signaling for resource locking, and hardware-supported port arbitration. It supports simultaneous read/write to the same address location without external logic.

RapidWrite mode enables back-to-back write cycles without pulsing R/W, CE, or BE signals-address transitions define cycle boundaries, reducing control overhead at 10 ns timing. Each port has independent OPT pins to configure I/O voltage (2.5 V or 3.3 V) and dedicated VDDQ supplies.

Key Specifications

Pinout & Package

70T651S10BF8 is housed in a 208-ball fpBGA (BF208) package with 0.8 mm pitch, 15 mm × 15 mm footprint, and 1.4 mm height. Power and ground balls are distributed across the array for low-inductance supply routing and thermal dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-port SRAM applications.

Compared with CY7C1362BV33-10BG and AS7C33256PFS-10BIN, the 70T651S10BF8 uniquely delivers industrial-grade dual-port operation with per-port I/O voltage flexibility and integrated hardware arbitration-enabling simpler, more robust real-time shared-memory designs.

Availability

70T651S10BF8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and avionics applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 70T651S10BF8 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

Integrated Device Technology (IDT), now part of Renesas Electronics, specializes in high-performance timing, memory interface, and RF solutions for communications and computing markets.

The 70T651S10BF8 belongs to IDT's high-speed dual-port SRAM product line, engineered for deterministic, low-latency inter-processor communication in mission-critical embedded systems.

FAQ

What is the maximum operating frequency supported by the 70T651S10BF8?

The 70T651S10BF8 does not operate at a fixed clock frequency-it is an asynchronous device. Its 10 ns read cycle time (tRC) supports effective data transfer rates up to 100 MHz in burst-read scenarios. Timing is governed by address, CE, OE, and BE setup/hold relationships-not a system clock. The 70T651S10BF8 achieves this performance with guaranteed tAA ≤ 10 ns and tACE ≤ 10 ns across the industrial temperature range.

Does the 70T651S10BF8 support true simultaneous read/write to the same memory location?

Yes, the 70T651S10BF8 implements true dual-port SRAM cells that permit concurrent read and write operations to the same address-provided they occur on separate ports. This eliminates bus contention and enables lock-free data exchange. The 70T651S10BF8 includes dedicated BUSY flags and hardware semaphore logic to manage cross-port synchronization when required.

How does RapidWrite mode function in the 70T651S10BF8, and what timing parameters change?

In RapidWrite mode, the 70T651S10BF8 defines write cycle boundaries by address transitions-not R/W or CE deassertion. R/W, CE, and BE remain asserted across consecutive writes. tAS and tWR become irrelevant between writes; instead, tDW and tDH reference the ending address transition. This reduces control logic complexity and maintains 10 ns write cycle integrity without narrow pulse generation-critical for FPGA-based controllers interfacing with the 70T651S10BF8.

Can the left and right ports of the 70T651S10BF8 operate at different I/O voltages simultaneously?

Yes-the 70T651S10BF8 supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL = VDD (2.5 V) configures the left port for 3.3 V I/O levels (with VDDQL = 3.3 V), while OPTR = VSS (0 V) sets the right port for 2.5 V I/O (with VDDQR = 2.5 V). This enables seamless interfacing between 3.3 V FPGAs and 2.5 V microcontrollers using a single 70T651S10BF8 device.

What is the role of the M/S pin in 70T651S10BF8 system-level design?

The M/S pin configures the 70T651S10BF8 as either Master (M/S = VIH) or Slave (M/S = VIL). In Master mode, BUSYL/BUSYR act as totem-pole outputs indicating local port busy state; in Slave mode, they serve as inputs for upstream arbitration. This enables daisy-chained configurations where one 70T651S10BF8 coordinates access across multiple devices-essential for building 72-bit or wider memory systems without external logic.