Infineon Technologies CY7C025-25JXC

Overview

CY7C025-25JXC 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 operates at 25 ns access time with 5 V ±10% supply. Used in interprocessor communication buffers and dual-port video frame stores.

For engineers reviewing the CY7C025-25JXC datasheet, CY7C025-25JXC pinout, CY7C025-25JXC application, or CY7C025-25JXC equivalent, key selection criteria include dual-port arbitration timing (tPS = 15 ns), semaphore latch count (8), BUSY/INT flag behavior in master/slave mode, and compatibility with 84-pin PLCC footprint for legacy board reuse.

Technical Context

The CY7C025-25JXC implements fully asynchronous dual-port operation with independent CE/R/W/OE controls per port, enabling concurrent reads/writes without external synchronization. Its on-chip arbitration resolves address-contention events within tPS = 15 ns, asserting BUSY to the losing port while granting deterministic access to the winning port.

Semaphore logic comprises eight dedicated latches accessible via SEM pin activation, with A0–A2 selecting latch index and I/O0 controlling token state (0 = claimed, 1 = released). INT flags use upper memory addresses (1FFFH for right-port mailbox, 1FFE H for left-port mailbox) to signal cross-port message arrival, cleared only upon mailbox read.

Key Specifications

Pinout & Package

Package: 84-pin Plastic Leaded Chip Carrier (PLCC), lead-free, body size 29.31 mm × 29.31 mm, JEDEC MS-026AC compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V25S25PF and CY7C028-25AC, the CY7C025-25JXC uniquely delivers full 5 V dual-port functionality-including master/slave expansion, 8 semaphores, and mailbox interrupts-in a through-hole PLCC package, enabling drop-in replacement in legacy industrial controllers without layout change.

Availability

CY7C025-25JXC is available at Aetrix Electronics and suitable for interprocessor communication buffers, dual-port video frame stores, industrial PLC I/O data exchange, and telecom line card status buffering requiring stable component supply across extended product lifecycles.

Supply support for CY7C025-25JXC 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) is a U.S.-based semiconductor company specializing in memory, microcontrollers, and programmable system-on-chip solutions for industrial, automotive, and communications markets.

The CY7C02x series was designed specifically for deterministic, low-latency interprocessor memory sharing-targeting applications where software-only synchronization introduces unacceptable jitter or race conditions.

FAQ

What is the function of the M/S pin on CY7C025-25JXC?

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, they accept BUSY input from a master device. This eliminates external logic for multi-chip wide-memory configurations and ensures deterministic timing alignment between chips during contention.

How do the semaphore latches operate in CY7C025-25JXC?

The eight semaphore latches are accessed via SEM pin activation and A0–A2 addressing. Writing 0 to a latch claims it (outputting 1 on the opposite port); writing 1 releases it. The latch state is read across all 16 I/O lines, and the output register holds the value during cross-port writes to prevent corruption-enabling atomic resource ownership transfer without software polling loops.

Can CY7C025-25JXC be used with 3.3 V logic interfaces?

No. CY7C025-25JXC requires 5 V ±10% (4.5–5.5 V) supply and is not 3.3 V tolerant. Input voltage limits are –0.5 V to +7.0 V, but DC switching thresholds and output drive levels are specified only for 5 V operation. Interfacing with 3.3 V systems requires level-shifting circuitry on all control and data lines to avoid undefined logic states or excessive current draw.

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

On-chip arbitration detects address matches within tPS = 15 ns and asserts BUSY to the losing port while granting exclusive access to the winning port. If tPS is violated, access is granted to one port but not guaranteed deterministically. The BUSY signal remains asserted until the winning port completes its cycle, preventing the losing port from initiating subsequent accesses to that location until BUSY deasserts.