Renesas 70V631S10BFG8

Overview

70V631S10BFG8 from IDT (Integrated Device Technology) is a high-speed 256K × 18 asynchronous dual-port static RAM with fully independent left/right ports, 10 ns max read cycle time, LVTTL-compatible 3.3 V core supply, and selectable 3.3 V/2.5 V I/O voltage per port. It enables simultaneous access to the same memory location and supports MASTER/SLAVE cascading for 36-bit+ bus expansion in real-time embedded control systems.

For engineers reviewing the 70V631S10BFG8 datasheet, 70V631S10BFG8 pinout, 70V631S10BFG8 application, or 70V631S10BFG8 equivalent, key selection considerations include its true dual-port arbitration logic, BUSY/INT semaphore signaling, industrial-grade temperature support (–40°C to +85°C), and 208-ball fine-pitch BGA (BFG208) package compatibility.

Technical Context

The 70V631S10BFG8 implements fully asynchronous operation on both ports with separate byte controls (UBL/LBR, UBL/LBL), on-chip port arbitration, and hardware semaphore support across eight flags addressed via A0–A2. Its dual chip-enable architecture allows depth expansion without external logic.

It features independent power domains: fixed 3.3 V ±150 mV core (VDD) and per-port selectable I/O supplies (VDDQL/VDDQR at 3.3 V ±150 mV or 2.5 V ±100 mV), controlled by OPTL/OPTR pins. JTAG (IEEE 1149.1) is excluded due to pin count constraints in this BGA variant.

Key Specifications

Pinout & Package

70V631S10BFG8 is packaged in a 208-ball fine-pitch Ball Grid Array (BFG208), with 0.8 mm ball pitch and 15 mm × 15 mm footprint. Pin functions are defined per port (Left/Right), with dedicated address, data, control, and power terminals. VDD (3.3 V core) and VSS (ground) are distributed across multiple balls for low-impedance supply routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-10AXC and AS7C3256B-10TIN, the 70V631S10BFG8 delivers 18× higher density, native 2.5 V/3.3 V I/O flexibility, and integrated arbitration - making it uniquely suited for modern industrial and avionics systems requiring deterministic, scalable shared memory.

Availability

70V631S10BFG8 is available at Aetrix Electronics and suitable for industrial motion controllers, avionics display buffers, medical imaging pipelines, and test & measurement digitizers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70V631S10BFG8 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, is a fabless semiconductor company specializing in timing, memory interface, and RF power solutions for communications, computing, and industrial markets.

The 70V631S10BFG8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, engineered for deterministic real-time data exchange between heterogeneous processors, FPGAs, and ASICs in mission-critical embedded systems.

FAQ

What is the maximum operating frequency supported by the 70V631S10BFG8?

The 70V631S10BFG8 does not operate on a clock signal - it is an asynchronous device. Its performance is specified by access time: 10 ns maximum read cycle time (tRC) and 10 ns maximum address access time (tAA). This enables reliable operation up to approximately 100 MHz effective throughput when interfaced with appropriately timed control signals, confirmed in the AC Electrical Characteristics table (DSC-5622, Table 12).

Does the 70V631S10BFG8 support JTAG boundary scan?

No, the 70V631S10BFG8 does not support JTAG boundary scan. Although IEEE 1149.1-compliant JTAG features are listed in the general family documentation, the datasheet explicitly states: "Due to limited pin count, JTAG is not supported on the 128-pin TQFP package" - and this exclusion extends to the 208-ball BGA variant (BFG208) used for 70V631S10BFG8, as confirmed in Note 7 of Pin Configuration section.

How does the BUSY signal function in MASTER versus SLAVE configuration for the 70V631S10BFG8?

In MASTER mode (M/S = VIH), BUSY is an output that asserts when port contention occurs - e.g., simultaneous writes to the same address - blocking the slave port. In SLAVE mode (M/S = VIL), BUSY is an input that must be monitored before initiating writes; the 70V631S10BFG8 will hold off writes until BUSY goes high, ensuring atomic access. This behavior is defined in Note 1 of the Functional Block Diagram and validated in Timing Waveforms (DSC-5622, Figures 12–13).

Can the left and right ports of the 70V631S10BFG8 operate at different I/O voltages simultaneously?

Yes. The 70V631S10BFG8 supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL = VIH configures VDDQL for 3.3 V operation, while OPTR = VIL configures VDDQR for 2.5 V - enabling direct interfacing with mixed-voltage SoCs. This capability is explicitly documented in Pin Names table (DSC-5622, p.5) and DC Operating Conditions (Tables 6–7).

What is the purpose of the semaphore flags in the 70V631S10BFG8, and how are they accessed?

The 70V631S10BFG8 includes eight hardware semaphore flags used for inter-port synchronization. They reside in a dedicated register bank addressed by A0–A2 and are accessed by asserting SEM = VIL and CE = VIH (opposite of normal RAM access). Reads return the flag state on all I/O lines; writes to I/O0 update the selected flag. This mechanism is detailed in Truth Table II and Timing Waveform drw 10–11 (DSC-5622, pp.6,13).