Renesas 70T633S10BCI8

Overview

70T633S10BCI8 from IDT (now Renesas) is a high-speed 512K × 18-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. It enables simultaneous access to the same memory location and supports MASTER/SLAVE cascading for 36-bit+ bus expansion in real-time inter-processor communication systems.

For engineers reviewing the 70T633S10BCI8 datasheet, 70T633S10BCI8 pinout, 70T633S10BCI8 application, or 70T633S10BCI8 equivalent, key selection criteria include true dual-port arbitration logic, RapidWrite Mode for back-to-back writes, JTAG IEEE 1149.1 compliance in BGA-256, industrial temperature support (–40°C to +85°C), and on-chip semaphore signaling for resource synchronization.

Technical Context

This device implements fully asynchronous operation-each port operates independently with separate address, control, and I/O buses. Its on-chip arbitration logic resolves port contention via BUSY flag assertion and supports hardware semaphore signaling across ports using dedicated SEM pins and A0–A2 address decoding.

The 70T633S10BCI8 integrates RapidWrite Mode, eliminating the need to toggle R/W between consecutive writes; instead, write termination is triggered by address transition, reducing timing overhead at 10 ns cycle times. Power management includes dual chip enables per port and ZZ sleep mode inputs that disable dynamic inputs while preserving JTAG functionality.

Key Specifications

Pinout & Package

70T633S10BCI8 is housed in a 256-ball fine-pitch BGA (package code BC256/BCG256) with 17 mm × 17 mm body and 1.0 mm ball pitch. Pin functions are strictly segregated per port (Left/Right), with dedicated VDD/VSS, VDDQ, OPT, and ZZ pins for each side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C028V-15AC and R1EX24024AS0A, the 70T633S10BCI8 delivers faster 10 ns access, industrial temperature support, integrated arbitration, and configurable I/O voltage - making it uniquely suited for real-time embedded systems requiring deterministic multi-processor memory sharing.

Availability

70T633S10BCI8 is available at Aetrix Electronics and suitable for industrial PLCs, avionics data concentrators, and medical imaging systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 70T633S10BCI8 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 leader in high-performance memory and interface solutions for real-time embedded systems.

The 70T633S10BCI8 belongs to IDT's high-speed asynchronous dual-port SRAM product line, designed specifically for deterministic inter-processor communication in industrial automation, aerospace, and medical equipment.

FAQ

What is the maximum operating frequency supported by the 70T633S10BCI8?

The 70T633S10BCI8 does not operate on a clock; it is an asynchronous device. Its 10 ns read cycle time (tRC) supports effective data throughput up to 100 MHz in tightly timed systems. Real-world bandwidth depends on system-level timing margins, load capacitance, and whether RapidWrite Mode is used to minimize inter-cycle gaps. The 70T633S10BCI8 achieves this performance with zero wait states under nominal conditions.

Does the 70T633S10BCI8 support both 2.5 V and 3.3 V I/O on the same device?

Yes - the 70T633S10BCI8 supports independent I/O voltage selection per port: OPTL configures the left port (VDDQL), and OPTR configures the right port (VDDQR). Either port can be set to 2.5 V (OPT = VSS) or 3.3 V (OPT = VDD), enabling mixed-voltage interfacing - for example, connecting a 2.5 V DSP to a 3.3 V FPGA via the same 70T633S10BCI8 device.

How does the BUSY flag function in MASTER/SLAVE configuration?

In MASTER mode (M/S = VIH), BUSYL/BUSYR are outputs asserting active-low when the opposing port initiates a conflicting access. In SLAVE mode (M/S = VIL), they become inputs used to detect master-initiated arbitration. This bidirectional behavior allows the 70T633S10BCI8 to serve as either endpoint in a two-device cascade - no external logic is needed to manage port priority or conflict resolution.

Is JTAG boundary scan available on all package variants of the 70T633S10BCI8?

JTAG IEEE 1149.1 compliance is explicitly specified for the BGA-256 and BGA-208 packages - including the 70T633S10BCI8 (BGA-256). It is not supported in smaller or leaded packages. The TCK, TMS, TDI, TDO, and TRST pins are dedicated and electrically isolated from functional I/O, allowing concurrent debug and operation without signal contention.

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

RapidWrite Mode allows consecutive write operations without pulsing R/W, CE, or byte enables between cycles - write termination is triggered by the next address transition. To enable it, hold R/W low and maintain CE and LB/UB asserted across address changes. This mode is confirmed in the 70T633S10BCI8 datasheet and reduces controller complexity in high-bandwidth streaming applications.