Renesas 70T633S10BCI

Overview

70T633S10BCI from IDT (now Renesas) is a high-speed 512K × 18-bit asynchronous dual-port static RAM with independent left/right ports, 10 ns max access time, 2.5V core supply, and selectable 2.5V/3.3V I/O interface per port. It supports true simultaneous read/write to the same memory location and is used in real-time inter-processor communication, FPGA co-processing buffers, and telecom packet buffering systems.

For engineers reviewing the 70T633S10BCI datasheet, 70T633S10BCI pinout, 70T633S10BCI application, or 70T633S10BCI equivalent, key selection considerations include its RapidWrite Mode for back-to-back writes, on-chip semaphore arbitration, BUSY/INT flag signaling, JTAG IEEE 1149.1 support, and industrial-grade –40°C to +85°C operation in BGA-256 package.

Technical Context

The 70T633S10BCI implements fully asynchronous dual-port architecture with separate address, control, and data buses per port, enabling concurrent access without external arbitration logic. Its on-chip port arbitration logic handles contention via BUSY flag assertion and supports MASTER/SLAVE cascading for 36-bit+ word expansion using M/S pin configuration.

RapidWrite Mode eliminates need to toggle R/W or CE between consecutive writes - write termination is triggered by address transition instead of control signal deassertion. The device also integrates JTAG boundary-scan test capability compliant with IEEE 1149.1, available only in BGA-208 and BGA-256 packages.

Key Specifications

Pinout & Package

70T633S10BCI is housed in a 256-ball fine-pitch Ball Grid Array (BGA) package with 1.0 mm ball pitch and 17 mm × 17 mm body size. All VDD pins require 2.5 V; VDDQ pins must be supplied at 2.5 V or 3.3 V depending on corresponding OPT pin state. Ground connections are distributed across 42 VSS balls for low-inductance return paths.

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 70T633S10BCI delivers unique value through integrated RapidWrite Mode (reducing control logic complexity), hardware semaphore (enabling lock-free IPC), and JTAG testability (supporting safety-critical validation), all within industrial temperature range and mixed-voltage I/O flexibility.

Availability

70T633S10BCI is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and aerospace data concentrators requiring stable component supply, long-term lifecycle assurance, and traceable sourcing from authorized channels.

Supply support for 70T633S10BCI 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, and interface solutions for communications, computing, and industrial markets.

The 70T633S10BCI belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for deterministic inter-processor communication in real-time embedded systems where latency, reliability, and hardware-assisted synchronization are critical.

FAQ

What is the maximum operating frequency supported by the 70T633S10BCI?

The 70T633S10BCI does not operate at a fixed clock frequency - it is an asynchronous SRAM with 10 ns maximum access time (tAA). This enables effective operation up to 100 MHz in random-access patterns, assuming proper setup/hold timing is met. Cycle time tRC is also 10 ns, supporting sustained back-to-back operations in RapidWrite Mode without clock constraints.

Does the 70T633S10BCI support both 2.5 V and 3.3 V I/O interfaces simultaneously?

Yes - the 70T633S10BCI 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, while OPTR = VSS (0 V) configures the right port for 2.5 V I/O. Both ports can operate at 3.3 V, both at 2.5 V, or mixed - with corresponding VDDQL/VDDQR supplies.

How does the BUSY flag function in MASTER/SLAVE configurations of the 70T633S10BCI?

In MASTER mode (M/S = VIH), BUSYL/BUSYR are totem-pole outputs asserting high during port contention. In SLAVE mode (M/S = VIL), they become inputs used to detect contention from the MASTER. This bidirectional behavior enables hardware handshaking in cascaded memory systems without external logic, directly supported by the 70T633S10BCI's internal arbitration logic.

Is JTAG boundary scan available on the 70T633S10BCI, and what are its limitations?

Yes - JTAG IEEE 1149.1 support is confirmed for the 70T633S10BCI in its BGA-256 package. TCK, TMS, TDI, TDO, and TRST pins are dedicated and functional. However, boundary scan operation is not recommended during sleep mode (ZZ asserted), and JTAG does not provide in-circuit programming - it is strictly for test and debug.

What is the purpose of the RapidWrite Mode in the 70T633S10BCI, and how is it enabled?

RapidWrite Mode allows consecutive write operations without toggling R/W, CE, or byte enables between cycles - write termination is triggered by address transition instead. It is enabled automatically when R/W, CE, and BEn remain asserted across address changes. The mode requires meeting tAAS (≤1 ns skew) and tARF (≥1.5 V/ns) specs to prevent spurious writes.