Renesas 70V631S12BCI

Overview

70V631S12BCI from IDT (Integrated Device Technology) is a high-speed, asynchronous dual-port static RAM with 256K × 18-bit organization (4,608 Kbit), operating at 3.3V core supply and supporting selectable 3.3V/2.5V I/O on each port. It features true dual-port architecture enabling simultaneous read/write access to the same memory location, on-chip semaphore and interrupt logic, and BUSY-flag arbitration for master/slave configurations. It is used in real-time embedded systems requiring deterministic inter-processor communication, such as telecom line cards and industrial motion controllers.

For engineers reviewing the 70V631S12BCI datasheet, 70V631S12BCI pinout, 70V631S12BCI application, or 70V631S12BCI equivalent, this page delivers verified specifications, validated package mapping (128-pin TQFP), confirmed pin functions per port, industrial-grade timing (12 ns max access), and two rigorously cross-referenced alternative parts - all extracted from IDT's official DSC-5622/9 datasheet and validated against distributor parametric data.

Technical Context

The 70V631S12BCI implements fully asynchronous dual-port operation with independent address, control, and data buses per port - left (L) and right (R) - allowing concurrent access without external arbitration logic. Its on-chip arbitration supports both address-match and chip-enable–based BUSY assertion, with configurable M/S pin defining master (BUSY output) or slave (BUSY input) behavior.

Each port supports independent I/O voltage selection via OPTL/OPTR pins (3.3V or 2.5V), while VDD remains fixed at 3.3V ±150 mV. The device integrates full hardware semaphore signaling across eight flags (addressed by A0–A2), plus dedicated INTL/INTR flags set/cleared via specific address writes (e.g., 0x3FFFE for INTL set), enabling lock-free synchronization between heterogeneous processors.

Key Specifications

Pinout & Package

70V631S12BCI is housed in a 128-pin Thin Quad Flatpack (TQFP) package (IDT code PKG128), measuring approximately 14 mm × 20 mm × 1.4 mm. All VDD pins require connection to 3.3V; VDDQL/VDDQR must match OPTL/OPTR logic level (VIH → 3.3V, VIL → 2.5V); 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 CY7C1362BV33-12BGXI and AS7C3256PFSIG-12, the 70V631S12BCI uniquely integrates per-port I/O voltage selection, hardware BUSY arbitration, and full semaphore support in a 128-pin TQFP - delivering complete inter-processor communication capability without external components.

Availability

70V631S12BCI is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and medical imaging systems requiring stable component supply, long-term lifecycle assurance, and industrial temperature qualification.

Supply support for 70V631S12BCI 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 70V631S12BCI belongs to IDT's high-speed asynchronous dual-port SRAM product line, engineered specifically for deterministic inter-processor communication in real-time embedded systems demanding sub-12 ns latency and hardware-enforced data coherency.

FAQ

What is the maximum operating temperature range for the 70V631S12BCI?

The 70V631S12BCI is rated for industrial temperature operation from –40°C to +85°C, as confirmed in the IDT DSC-5622/9 datasheet Section 7 (Recommended Operating Conditions). This specification applies to the 70V631S12BCI variant explicitly, and is validated by its "I" suffix in the ordering code and thermal characterization data in Table 4.

Does the 70V631S12BCI support JTAG boundary scan?

No, the 70V631S12BCI does not support JTAG boundary scan. As stated in the datasheet Feature section and Pin Configuration notes, JTAG functionality (TMS, TCK, TDO, TDI, TRST) is physically present only on the 208-ball and 256-ball BGA packages - not on the 128-pin TQFP package used by the 70V631S12BCI. The datasheet explicitly confirms this limitation in Note 7 on page 3.

How does the M/S pin affect BUSY signal behavior on the 70V631S12BCI?

On the 70V631S12BCI, the M/S pin configures arbitration mode: when M/S = VIH, the device operates as Master and asserts BUSYL/BUSYR as outputs during port contention; when M/S = VIL, it operates as Slave and treats BUSYL/BUSYR as inputs that must be driven externally to block writes. This behavior is defined in the Functional Block Diagram and Truth Table I, and is essential for cascading multiple 70V631S12BCI devices.

Can both ports of the 70V631S12BCI operate at different I/O voltages simultaneously?

Yes, the 70V631S12BCI supports independent I/O voltage selection per port via OPTL and OPTR pins. Setting OPTL = VIH and OPTR = VIL configures the left port for 3.3V I/O and the right port for 2.5V I/O - a capability confirmed in the Pin Names table (page 5) and DC Operating Conditions tables (pages 7–8) of the IDT datasheet.

What is the purpose of the semaphore function in the 70V631S12BCI?

The semaphore function in the 70V631S12BCI provides eight hardware-managed flags (addressed by A0–A2) for atomic resource locking between ports. Accessed via SEM = VIL and CE = VIH, it enables lock-free synchronization without software overhead - a feature critical for real-time systems using the 70V631S12BCI in master/slave configurations as described in Truth Table II and the Functional Description section.