Infineon Technologies CY7C028V-25AC

Overview

CY7C028V-25AC from Cypress Semiconductor is a 64K × 16-bit true dual-port static RAM with independent left/right ports, 25 ns maximum access time, 3.3 V supply, and integrated arbitration logic including semaphores and BUSY/INT flags. It enables simultaneous asynchronous read/write to the same memory location in interprocessor communication systems.

For engineers reviewing the CY7C028V-25AC datasheet, CY7C028V-25AC pinout, CY7C028V-25AC application, or CY7C028V-25AC equivalent, key selection criteria include dual-port arbitration behavior, byte-select control (UBL/LBL), M/S pin configuration for master/slave expansion, and ISB3 standby current of 10 µA at CMOS-level chip disable.

Technical Context

This device implements fully asynchronous dual-port operation with on-chip arbitration logic that resolves port contention via BUSY flag assertion and software-controlled semaphores - eight shared latches enabling token-based resource locking between processors. Each port has dedicated CE0/CE1, R/W, OE, and byte-enable (UBL/LBL) controls.

It supports expandable data bus architectures: multiple CY7C028V-25AC units can be cascaded using Master/Slave (M/S) pin configuration to build 32-bit or wider dual-port memory without external logic. The device operates across commercial temperature range (0°C to +70°C) with 3.3 V ±300 mV supply tolerance.

Key Specifications

Pinout & Package

Package: 100-pin Thin Quad Flatpack (TQFP), 14 mm × 14 mm body, 0.5 mm pitch, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V27L-25JGI, CY7C028V-25AC provides hardware arbitration and expandability without added components; versus CY7C028V-25AXC, it trades extended temperature support for lower cost and tighter commercial-spec leakage.

Availability

CY7C028V-25AC is available at Aetrix Electronics and suitable for interprocessor communication buffers, dual-port video frame buffers, and telecom protocol stack buffers requiring stable component supply and long-term obsolescence management.

Supply support for CY7C028V-25AC 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-reliability memory and programmable solutions for embedded systems, emphasizing low-power, mixed-signal integration, and industrial longevity.

CY7C028V belongs to the CY7C02xV dual-port SRAM product line, engineered specifically for deterministic, contention-free memory sharing between heterogeneous processors in real-time control and communications infrastructure.

FAQ

What is the function of the M/S pin on CY7C028V-25AC?

The M/S (Master/Slave) pin configures the device for use in expanded memory systems: when HIGH, it operates as a master driving BUSY output; when LOW, it acts as a slave accepting BUSY input from another device. This enables 32-bit or wider dual-port memory stacks using identical CY7C028V-25AC units without external glue logic or dedicated slave parts.

How does the semaphore logic work in CY7C028V-25AC?

The device integrates eight hardware semaphore latches accessible via SEML/SEMR and dedicated address lines. Each latch functions as a binary flag: one port asserts it to claim a shared resource (e.g., a buffer or peripheral), and the other port reads it before attempting access. The latches are mutually exclusive - only one port may write to a given semaphore at a time - ensuring atomic resource locking without software race conditions.

Can CY7C028V-25AC operate with 5 V logic interfaces?

No. CY7C028V-25AC is a 3.3 V-only device: absolute maximum input voltage is VCC + 0.5 V (≤ 3.8 V), and VIH is specified at 2.2 V minimum. Direct connection to 5 V logic will exceed voltage ratings and risk permanent damage. Level-shifting circuitry is required for interfacing with 5 V controllers or FPGAs lacking 3.3 V I/O banks.

What is the significance of ISB3 = 10 µA in system design?

ISB3 represents the current drawn when both ports are disabled with chip enables held at CMOS-high levels (≥ VCC − 0.2 V) and no signal transitions - the deepest hardware sleep mode. At 10 µA typical, it enables battery-backed or energy-harvested systems to retain full memory contents for months without recharge, making it suitable for remote sensors, metering endpoints, and always-on communication gateways.