Infineon Technologies CY7C025-15AXI

Overview

CY7C025-15AXI from Cypress Semiconductor is an 8K × 16-bit true dual-port static RAM with on-chip arbitration, semaphores, and INT/BUSY flags. It enables simultaneous asynchronous read/write access to shared memory by two independent processors or data paths, supports master/slave expansion to 32-bit bus width, and delivers 15 ns access time at 5 V. It is used in interprocessor communication buffers and real-time video/graphics frame stores.

For engineers reviewing the CY7C025-15AXI datasheet, CY7C025-15AXI pinout, CY7C025-15AXI application, or CY7C025-15AXI equivalent, key selection criteria include dual-port arbitration behavior, semaphore latch count, BUSY flag timing (tBLA/tBLC), M/S pin configuration for master/slave cascading, and Pb-free 100-pin TQFP package compatibility with industrial temperature range (–40°C to +85°C).

Technical Context

The CY7C025-15AXI implements fully asynchronous dual-port operation with independent CE/R/W/OE control per port, enabling concurrent reads/writes to any memory location. Its on-chip arbitration logic resolves contention via deterministic BUSY assertion (tBLA = 5 ns, tBLC = 8 ns) and guarantees exclusive access without external logic.

It integrates eight dedicated semaphore latches accessible via SEM pin, supporting software-controlled resource locking across ports; each semaphore is write-protected-only the side that successfully writes '0' can modify it until released. The INT flag uses upper two memory addresses (1FFFH/1FFE H) as mailboxes for port-to-port interrupt signaling, reset upon mailbox read.

Key Specifications

Pinout & Package

CY7C025-15AXI is housed in a 100-pin Thin Quad Plastic Flatpack (TQFP), Pb-free, with 0.5 mm pitch and exposed thermal pad. Pin functions are strictly asymmetric: left port (L) and right port (R) share no signal names except power/ground and M/S.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V25S15YG and CY7C028-15AC, CY7C025-15AXI uniquely combines industrial-temp 5 V operation, Pb-free 100-pin TQFP packaging, integrated M/S expansion, and hardware semaphores - making it optimal for cost-sensitive, legacy 5 V embedded systems requiring deterministic interprocessor coordination.

Availability

CY7C025-15AXI is available at Aetrix Electronics and suitable for interprocessor communication buffers, dual-port video frame stores, industrial PLC I/O mapping tables, and telecom line card status buffers requiring stable component supply across extended product lifecycles.

Supply support for CY7C025-15AXI 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) is a fabless semiconductor company specializing in memory, PSoC, USB, and timing solutions for industrial, automotive, and communications markets.

The CY7C02x family was designed specifically for deterministic, low-latency interprocessor memory sharing - emphasizing on-chip arbitration, semaphores, and expandable bus architecture over raw density or speed.

FAQ

What is the function of the M/S pin in CY7C025-15AXI?

The M/S pin configures the device as master (HIGH) or slave (LOW) for 32-bit bus expansion. In master mode, BUSY pins output arbitration results; in slave mode, BUSY pins accept arbitration signals from a master. This eliminates external logic for multi-chip wide-memory systems and ensures deterministic timing alignment between chips.

How do the semaphore latches prevent resource conflicts between ports?

Each of the eight semaphores operates as a write-protected flag: only the port that first writes '0' gains ownership and exclusive write access. The other port reads '1' and must poll until ownership is released (by writing '1'). This hardware-enforced mutual exclusion avoids software race conditions and guarantees atomic resource allocation without CPU intervention.

Can CY7C025-15AXI operate with mixed voltage interfaces (e.g., 5 V core, 3.3 V I/O)?

No. CY7C025-15AXI is a single-supply 5 V ±10% device. All I/Os (including control pins) are TTL-compatible and require 5 V logic levels. Interfacing with 3.3 V systems necessitates level-shifting circuitry on all 32 data lines and 12+ control signals - no built-in voltage translation is provided.

What happens when both ports attempt to access the same memory location simultaneously?

On-chip arbitration asserts BUSY on the losing port within 5 ns (tBLA) of address match. The winning port proceeds with read/write; the losing port's access is blocked until BUSY deasserts. If contention occurs outside timing window tPS (10 ns), outcome is undefined - design must ensure address setup meets tPS to guarantee deterministic resolution.