Renesas 70T3539MS166BC8

Overview

70T3539MS166BC8 from IDT (now Renesas) is a high-speed synchronous dual-port SRAM with true dual-port architecture, 512K × 36-bit organization (18 Mb), 2.5V core supply, and selectable 2.5V/3.3V I/O interfaces per port. It supports simultaneous independent read/write access on left and right ports with pipelined or flow-through output modes, enabling real-time data exchange in telecom packet buffers and FPGA co-processor memory subsystems.

For engineers reviewing the 70T3539MS166BC8 datasheet, 70T3539MS166BC8 pinout, 70T3539MS166BC8 application, or 70T3539MS166BC8 equivalent, key selection criteria include its 166 MHz operation (6 ns cycle time), dual-cycle deselect for pipelined mode, JTAG boundary scan support, industrial temperature range (–40°C to +85°C), and 256-pin BGA package with independent voltage control per port.

Technical Context

This device implements fully synchronous dual-port operation with separate clock, address, data, and control registers on each port. Its internal architecture includes dual address strobe logic (ADSL/ADSR), counter-enable and repeat-address functionality, and collision/interrupt flag generation for inter-port coordination.

The memory array uses true dual-port cells enabling concurrent access to identical addresses without arbitration. Each port features independently configurable I/O voltage (via OPTL/OPTR), sleep mode (ZZL/ZZR), and output timing mode (PL/FTL & PL/FTR), allowing heterogeneous system integration - e.g., one port interfacing a 2.5V FPGA fabric while the other connects to a 3.3V legacy controller.

Key Specifications

Pinout & Package

70T3539MS166BC8 is housed in a 256-pin Ball Grid Array (BGA) package with 17 mm × 17 mm body size and 1.0 mm ball pitch. All VDD pins require connection to 2.5 V; VDDQ pins must be set to 2.5 V or 3.3 V depending on OPT pin configuration per port; 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 CY7C1362BV33-166AXC and AS7C331024B-166BIN, the 70T3539MS166BC8 uniquely combines 2.5V core with flexible per-port I/O voltage, pipelined timing, JTAG testability, and hardware collision/interrupt signaling - making it the only choice for high-reliability, mixed-voltage, real-time embedded systems requiring deterministic dual-port behavior.

Availability

70T3539MS166BC8 is available at Aetrix Electronics and suitable for telecom infrastructure, industrial motion control, avionics data acquisition, and FPGA-based embedded systems requiring stable component supply across extended product lifecycles.

Supply support for 70T3539MS166BC8 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

Renesas Electronics (formerly Integrated Device Technology, IDT) is a global semiconductor leader specializing in high-performance memory, timing, and connectivity solutions for industrial, automotive, and communications markets.

The 70T3539M family was designed specifically for real-time, low-latency dual-access memory applications in network processors, FPGAs, and safety-critical controllers - emphasizing deterministic timing, mixed-voltage interoperability, and on-chip diagnostics.

FAQ

What is the maximum operating frequency of the 70T3539MS166BC8, and under what conditions is it guaranteed?

The 70T3539MS166BC8 is rated for 166 MHz operation in commercial temperature range (0°C to +70°C), with a guaranteed 6 ns clock cycle time (tCYC2) in pipelined mode. This specification assumes VDD = 2.5 V ±100 mV, VDDQ = 3.3 V ±150 mV or 2.5 V ±100 mV per port, and proper signal integrity per AC Test Conditions (Figure 1). Industrial-grade operation is specified up to 133 MHz (7.5 ns cycle time).

How does the 70T3539MS166BC8 handle simultaneous access to the same memory location from both ports?

The 70T3539MS166BC8 uses true dual-port memory cells that permit simultaneous read/write access to identical addresses without conflict. When both ports access the same location, the device asserts COLL (collision alert) flags on both ports within 4.2 ns (tCOLS max), allowing external logic or firmware to resolve contention. No data corruption occurs - the last write wins deterministically based on relative clock phase alignment.

Can the left and right ports of the 70T3539MS166BC8 operate at different I/O voltage levels?

Yes. The 70T3539MS166BC8 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 operation (requiring VDDQL = 3.3 V), while OPTR = VSS (0 V) configures the right port for 2.5 V I/O (requiring VDDQR = 2.5 V). This enables direct interfacing with heterogeneous voltage domains without external level shifters.

What is the purpose of the REPEAT and CNTEN signals in the 70T3539MS166BC8 address counter function?

CNTEN enables automatic address increment on each clock edge when asserted low; ADSL/ADSR loads the initial address. REPEAT, when asserted, resets the internal counter to the last valid ADS-loaded address - enabling burst transfers to a fixed buffer region or circular buffer wraparound. This eliminates software overhead for address management in DMA-like operations.

Does the 70T3539MS166BC8 support boundary scan testing, and which pins are involved?

Yes. The 70T3539MS166BC8 includes IEEE 1149.1-compliant JTAG boundary scan with dedicated pins: TCK (Test Clock), TMS (Test Mode Select), TDI (Test Data In), TDO (Test Data Out), and TRST (Test Reset). These pins operate at VDD-referenced logic levels (1.7 V to VDD + 0.1 V) and remain functional even in sleep mode (ZZ asserted), enabling in-system test during power-down states.