Renesas 70T651S10BCI8

Overview

70T651S10BCI8 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-designed for real-time inter-processor communication in telecom switching fabric and packet buffer applications.

For engineers reviewing the 70T651S10BCI8 datasheet, 70T651S10BCI8 pinout, 70T651S10BCI8 application, or 70T651S10BCI8 equivalent, this page delivers verified package mapping (256-ball BGA, BC256), true dual-port arbitration logic, RapidWrite mode timing, JTAG-compliant test interface, and industrial-grade (-40°C to +85°C) operation with sleep-mode power control.

Technical Context

The 70T651S10BCI8 implements fully asynchronous dual-port architecture with on-chip arbitration, semaphore signaling, and master/slave cascading support-enabling simultaneous access to the same memory location without external logic. It supports independent voltage selection per port via OPTL/OPTR pins, allowing mixed 2.5 V/3.3 V I/O operation while maintaining a unified 2.5 V core supply.

Its RapidWrite mode eliminates R/W signal toggling between consecutive writes, reducing control overhead at 10 ns cycle times. The device features non-tri-state BUSY/INT flags, totem-pole outputs, and JTAG IEEE 1149.1 compliance-including TCK (10 MHz), TMS, TDI, TDO, and TRST-with sleep mode (ZZL/ZZR) disabling dynamic inputs except JTAG.

Key Specifications

Pinout & Package

70T651S10BCI8 is housed in a 256-ball fine-pitch BGA (package code BC256), with 17 mm × 17 mm footprint and 1.0 mm ball pitch. Power and ground balls are distributed across the array for low-inductance decoupling; VDD (2.5 V core) and VDDQ (2.5 V/3.3 V I/O) are segregated per port.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-10BGXI and AS7C331024B-10BIN, the 70T651S10BCI8 uniquely combines per-port I/O voltage selection, hardware semaphore, RapidWrite mode, and M/S cascading-enabling simpler, more deterministic system-level designs in heterogeneous, real-time embedded systems.

Availability

70T651S10BCI8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, automotive ADAS, and medical imaging systems requiring stable component supply, long-term lifecycle assurance, and industrial temperature performance.

Supply support for 70T651S10BCI8 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 70T651S10BCI8 belongs to IDT's high-speed dual-port SRAM product line, engineered specifically for deterministic, low-latency inter-processor communication in telecom switches, industrial controllers, and real-time embedded systems.

FAQ

What is the maximum operating frequency supported by the 70T651S10BCI8?

The 70T651S10BCI8 does not operate on a clock signal-it is an asynchronous SRAM. Its performance is defined by access timing parameters: 10 ns maximum address access time (tAA) and 10 ns read cycle time (tRC) under commercial conditions. These values guarantee deterministic latency for burst transfers without clock domain constraints, making it ideal for systems where timing predictability matters more than clock rate.

Does the 70T651S10BCI8 support both 2.5 V and 3.3 V I/O on the same device?

Yes-the 70T651S10BCI8 supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL to VDD (2.5 V) configures the left port for 3.3 V I/O (with VDDQL = 3.3 V), while setting OPTR to VSS (0 V) configures the right port for 2.5 V I/O (with VDDQR = 2.5 V). This enables seamless interfacing with mixed-voltage SoCs and FPGAs without level shifters.

How does the RapidWrite mode function in the 70T651S10BCI8?

In RapidWrite mode, the 70T651S10BCI8 allows consecutive write operations without pulsing R/W, CE, or BE signals high between cycles. The end of each write is defined by the next address transition-not R/W deassertion-reducing control complexity and enabling tighter write bursts at 10 ns cycle times. All standard timing specs (tWC, tDW, tDH) still apply, referenced to the ending address edge.

Can the 70T651S10BCI8 be used in a Master/Slave configuration for wider data buses?

Yes-the 70T651S10BCI8 supports hardware Master/Slave cascading via the M/S pin. When configured as Master (M/S = VIH), BUSYR/BUSYL become outputs; as Slave (M/S = VIL), they become inputs. This enables automatic busy-flag propagation across multiple devices, allowing expansion to 72-bit or wider word widths without external logic-verified in IDT reference designs for telecom line cards.

Is JTAG boundary scan supported on the 70T651S10BCI8, and does it remain functional in sleep mode?

Yes-the 70T651S10BCI8 fully complies with IEEE 1149.1 JTAG, featuring TCK (10 MHz max), TMS, TDI, TDO, and TRST pins. Critically, JTAG remains operational even when ZZL/ZZR are asserted (sleep mode), as the specification explicitly excludes JTAG inputs from sleep-mode shutdown-enabling in-system test and debug without waking the core memory array.