Renesas 70T633S12BC8

Overview

IDT70T633S12BC8 from Integrated Device Technology is a high-speed 512K × 18-bit asynchronous dual-port static RAM with independent left/right ports, 12 ns max access time, 2.5 V core supply, and selectable 2.5 V/3.3 V 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 systems requiring deterministic latency and hardware semaphore arbitration.

For engineers reviewing the 70T633S12BC8 datasheet, 70T633S12BC8 pinout, 70T633S12BC8 application, or 70T633S12BC8 equivalent, key selection criteria include dual-port timing compatibility, BUSY/INT flag behavior in MASTER/SLAVE cascading, RapidWrite Mode support for back-to-back writes, and BGA-256 package thermal/mechanical constraints in high-density PCB layouts.

Technical Context

The 70T633S12BC8 implements fully asynchronous operation with separate address, control, and data buses per port, enabling independent read/write cycles without clock synchronization. Its on-chip arbitration logic handles port contention via hardware semaphore signaling and BUSY flag handshaking between MASTER and SLAVE configurations.

RapidWrite Mode eliminates the need to toggle R/W or CE between consecutive writes-address transition defines cycle boundary-reducing system timing overhead at 12 ns cycle times. JTAG IEEE 1149.1 compliance is supported only in BGA-256 and BGA-208 packages, with TCK up to 10 MHz.

Key Specifications

Pinout & Package

70T633S12BC8 is housed in a 256-ball fine-pitch Ball Grid Array (BGA) package with 1.0 mm ball pitch, 17 mm × 17 mm body size, and 1.4 mm height. Thermal pad is not present; thermal management relies on PCB copper area and via stitching beneath the package.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1362BV33-12BGXI and AS7C331024B-12BIN, the 70T633S12BC8 uniquely delivers hardware semaphore arbitration, RapidWrite Mode, and per-port I/O voltage selection-enabling lower system BOM cost, reduced FPGA logic, and deterministic real-time performance in MASTER/SLAVE topologies.

Availability

70T633S12BC8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, avionics, and medical imaging systems requiring stable component supply, long-term lifecycle assurance, and traceable green-part sourcing.

Supply support for 70T633S12BC8 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, designs high-performance timing, memory, and interface solutions for communications, computing, and industrial markets.

The IDT70T633 family targets deterministic real-time systems requiring hardware-managed memory coherency between independent processors or ASICs-optimized for low-latency inter-processor communication with minimal external logic.

FAQ

What is the maximum operating frequency supported by the 70T633S12BC8?

The 70T633S12BC8 does not operate on a clock; it is an asynchronous dual-port SRAM. Its timing is defined by access and cycle parameters-not frequency. The 12 ns access time (tAA) and 12 ns cycle time (tRC) enable effective operation at up to ~83 MHz in tightly controlled systems, but actual throughput depends on system-level timing margins, bus loading, and control signal setup/hold compliance. No internal PLL or clock multiplier is present.

Can the left and right ports of the 70T633S12BC8 operate at different I/O voltages simultaneously?

Yes. The 70T633S12BC8 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) configures the right port for 2.5 V I/O with VDDQR = 2.5 V. This enables direct interfacing with mixed-voltage SoCs or FPGAs without external level shifters.

How does the BUSY flag function in MASTER versus SLAVE configuration for the 70T633S12BC8?

In MASTER configuration (M/S = VIH), BUSYL and BUSYR are totem-pole outputs that assert active-high when the opposite port initiates a write to an address currently being read. In SLAVE configuration (M/S = VIL), BUSYL and BUSYR become inputs-used to receive BUSY signals from the MASTER device in cascaded systems. Both modes are non-tri-state; pull-ups are not required.

Does the 70T633S12BC8 support JTAG boundary scan, and what are the requirements?

Yes, the 70T633S12BC8 supports IEEE 1149.1 JTAG boundary scan-but only in BGA-256 and BGA-208 packages (not in smaller variants). Required signals are TCK (≤10 MHz), TMS, TDI, TDO, and TRST. JTAG remains functional during sleep mode (ZZ asserted), but boundary scan operations are not recommended while ZZ is active due to potential I/O state instability.

What is the purpose of RapidWrite Mode in the 70T633S12BC8, and how is it enabled?

RapidWrite Mode in the 70T633S12BC8 allows consecutive write operations without toggling R/W, CE, or byte enables between cycles-address transition defines the end of each write. It is enabled automatically when R/W is held low across address changes. Designers must meet tAAS (≤1 ns address skew) and tARF (≥1.5 V/ns rise/fall) to prevent spurious writes; no register setting or command sequence is required.