Renesas 70T3339S166BC8

Overview

70T3339S166BC8 from Integrated Device Technology is a high-speed synchronous dual-port static RAM with 512K × 18-bit organization, 2.5V core supply, and selectable 2.5V/3.3V I/O interface per port. It supports pipelined or flow-through output modes, features dual chip enables for depth expansion, and delivers 3.6ns access time at 166MHz for commercial and industrial temperature ranges (–40°C to +85°C). It is used in real-time packet buffering, FPGA co-processor memory, and telecom line-card data path synchronization.

For engineers reviewing the 70T3339S166BC8 datasheet, 70T3339S166BC8 pinout, 70T3339S166BC8 application, or 70T3339S166BC8 equivalent, key selection criteria include simultaneous dual-port read/write capability, JTAG-compliant IEEE 1149.1 test support, collision/interrupt flag signaling, and independent voltage configuration per port via OPT pins - all critical for deterministic low-latency inter-processor communication.

Technical Context

This device implements true dual-port SRAM architecture with fully synchronous operation on both left and right ports, using edge-triggered registers for address, data, and control inputs to minimize setup/hold requirements. Its self-timed write cycle enables fast 5ns minimum clock cycle time in pipelined mode.

The memory supports independent port configuration: each port can operate at either 2.5V or 3.3V I/O levels via dedicated OPTL/OPTR pins, with corresponding VDDQL/VDDQR supplies. Collision detection and interrupt flags are generated synchronously to CLK, and address counter logic enables burst-mode sequential access with ADS strobe and REPEAT reset functionality.

Key Specifications

Pinout & Package

70T3339S166BC8 is housed in a 256-pin Ball Grid Array (BC256) package with 1.0mm ball pitch and 17mm × 17mm footprint. All VDD pins require connection to 2.5V; VDDQ pins must match OPT pin state (2.5V if OPT = VSS, 3.3V if OPT = VDD).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C1375DV33-167BZXI and AS7C331024B-167BIN, the 70T3339S166BC8 uniquely provides per-port voltage selection, hardware collision detection, and JTAG testability - making it the only option among the three qualified for mixed-voltage, safety-critical, or boundary-scan–required designs.

Availability

70T3339S166BC8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLC, and avionics data concentrator applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for 70T3339S166BC8 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 power solutions for communications and computing markets.

The 70T3339S166BC8 belongs to IDT's high-speed synchronous dual-port SRAM product line, designed specifically for deterministic, low-latency inter-processor communication in telecom, industrial automation, and aerospace systems.

FAQ

What is the maximum operating frequency of the 70T3339S166BC8 in pipelined mode?

The 70T3339S166BC8 supports up to 166MHz operation in pipelined mode, with a minimum clock cycle time (tCYC2) of 6ns. This is validated for both commercial and industrial temperature ranges. The 200MHz speed grade (S200) is not available in the BC256 package variant - only in fpBGA packages - so the 70T3339S166BC8 is rated for 166MHz maximum sustained operation.

How does the 70T3339S166BC8 handle simultaneous access to the same memory location from both ports?

The 70T3339S166BC8 uses true dual-port SRAM cells that allow simultaneous read/write access to the same address. When contention occurs, the COLL/INT flags assert within 3.6ns to signal collision, and internal arbitration ensures data integrity without bus locking. The 70T3339S166BC8 does not stall either port - both continue operation with deterministic timing, making it suitable for real-time inter-processor messaging.

Can the left and right ports of the 70T3339S166BC8 operate at different I/O voltage levels?

Yes - the 70T3339S166BC8 supports independent I/O voltage configuration per port via OPTL and OPTR pins. Setting OPTL = VDD configures the left port for 3.3V I/O levels (with VDDQL = 3.3V), while OPTR = VSS sets the right port to 2.5V I/O (with VDDQR = 2.5V). This capability is explicitly documented in the DC operating conditions tables and enables direct interfacing with heterogeneous logic families without external level shifters.

What is the purpose of the ADS and REPEAT signals in the 70T3339S166BC8 address counter function?

The ADS (Address Strobe) signal latches the current address into the internal counter register, while REPEAT resets the counter to that latched address on the next clock edge. This allows burst-mode sequential access without external address generation logic. For example, after ADS loads address A0, asserting REPEAT causes subsequent accesses to repeat A0 - a feature used in FIFO-like buffering or repeated register reads. This behavior is confirmed in Truth Table II and applies identically to both ports of the 70T3339S166BC8.

Does the 70T3339S166BC8 support boundary-scan testing, and what are the JTAG requirements?

Yes, the 70T3339S166BC8 fully supports IEEE 1149.1 boundary-scan testing with dedicated TDI, TDO, TCK (≤10MHz), TMS, and TRST pins. JTAG operation remains functional even during ZZ sleep mode, though the datasheet recommends avoiding boundary scan during sleep. All scan chain behavior - including instruction register loading and data register shifting - is verified per IEEE 1149.1 specification, and the 70T3339S166BC8 includes mandatory IDCODE and BYPASS instructions.