Infineon Technologies CYDM256B16-55BVXIT

Overview

CYDM256B16-55BVXIT from Cypress Semiconductor is a 16K × 16-bit (256 Kbit), 1.8 V asynchronous dual-port static RAM with true independent port access, 55 ns maximum access time, on-chip arbitration logic, and industrial temperature range (–40°C to +85°C). It enables simultaneous read/write operations to the same memory location in interprocessor communication systems.

For engineers reviewing the CYDM256B16-55BVXIT datasheet, CYDM256B16-55BVXIT pinout, CYDM256B16-55BVXIT application, or CYDM256B16-55BVXIT equivalent, key selection criteria include dual-port contention resolution timing, port-independent I/O voltage support (1.8/2.5/3.0 V), semaphore-based software handshaking, and 100-ball vfBGA package compatibility with high-density PCB layouts.

Technical Context

The device implements fully asynchronous dual-port architecture with separate address, data, and control buses per port (left/right), enabling concurrent access without external arbitration logic. Each port features independent Chip Enable (CE), Read/Write (R/W), Output Enable (OE), BUSY, and INT signals, plus dedicated upper/lower byte controls (UB/LB) and semaphore enable (SEM).

On-chip arbitration resolves memory contention via deterministic BUSY assertion (tBLA/tBLC), while eight shared semaphores provide software-controlled resource locking. The M/S pin configures master/slave operation for 32-bit bus expansion, and automatic power-down is triggered per-port by CE deassertion - supporting ultra-low standby current (2 µA typical at 1.8 V).

Key Specifications

Pinout & Package

Package: 100-ball, 0.5 mm pitch, 6 × 6 mm Pb-free very thin Fine-Pitch Ball Grid Array (vfBGA), RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V27L15PF and IS61WV102416BLL-10TLI, CYDM256B16-55BVXIT uniquely delivers ultra-low 2 µA standby current, flexible 1.8/2.5/3.0 V I/O support per port, and integrated semaphores - making it optimal for power-constrained, mixed-voltage, multi-processor systems requiring deterministic resource sharing.

Availability

CYDM256B16-55BVXIT is available at Aetrix Electronics and suitable for interprocessor communication, dual-port video buffering, and communications protocol stack buffering requiring stable component supply across industrial temperature ranges and long-term production cycles.

Supply support for CYDM256B16-55BVXIT 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

Cypress Semiconductor (now part of Infineon Technologies) designs high-performance memory and programmable solutions for embedded systems, with expertise in low-power SRAM, PSoC, and USB-C controllers.

CYDM256B16 belongs to the MoBL® (Mobile Bonding Low-power) Dual-Port SRAM product line, engineered specifically for deterministic, low-latency, low-power shared memory in multi-processor and real-time communication architectures.

FAQ

What is the function of the M/S pin on CYDM256B16-55BVXIT?

The M/S (Master/Slave) pin configures the device for 32-bit bus expansion: when HIGH, it operates as a master with BUSYR as output; when LOW, as a slave with BUSYR as input. This enables daisy-chained arbitration without external logic, supporting scalable memory width in multi-chip systems.

Does CYDM256B16-55BVXIT support independent I/O voltages on left and right ports?

Yes - VDDIOL and VDDIOR pins allow independent 1.8 V, 2.5 V, or 3.0 V I/O operation per port. This permits direct interfacing with heterogeneous processors (e.g., 1.8 V FPGA + 3.0 V MCU) without level shifters, reducing BOM count and signal integrity risk.

How does the semaphore feature work in practice?

The eight on-chip semaphores act as shared latches controlled exclusively by one port at a time. When a port asserts SEML/SEMR and writes to a semaphore address, it gains exclusive access to a shared resource - preventing simultaneous access and eliminating software race conditions in multi-processor environments.

Can CYDM256B16-55BVXIT operate at 2.5 V core voltage?

No - VCC must be 1.8 V, 2.5 V, or 3.0 V, but the device is specified for 1.8 V core operation in the -55BVXIT speed grade. At 2.5 V VCC, typical operating current rises to 28 mA and access time remains 55 ns; however, the -55BVXIT marking denotes 1.8 V optimized performance and qualification.