Infineon Technologies CY7C025-25JC

Overview

CY7C025-25JC from Cypress Semiconductor is an 8K × 16-bit true dual-port static RAM with on-chip arbitration, semaphores, and INT/BUSY flags for interprocessor communication. It operates at 5 V ±10%, supports 25 ns access time, delivers 150 mA typical active current, and is packaged in an 84-pin PLCC. It enables simultaneous asynchronous read/write access to shared memory in multiprocessor systems.

For engineers reviewing the CY7C025-25JC datasheet, CY7C025-25JC pinout, CY7C025-25JC application, or CY7C025-25JC equivalent, key selection considerations include dual-port arbitration timing (tPS = 10 ns), semaphore latch behavior, master/slave expandability via M/S pin, and BUSY flag assertion timing (tBLA = 12 ns) in contention scenarios.

Technical Context

The CY7C025-25JC implements fully asynchronous dual-port architecture with independent left/right control paths (CE, R/W, OE, UB/LB), enabling concurrent access without external synchronization. Its on-chip arbitration logic resolves address-contention events within 10 ns (tPS), asserting BUSY to the losing port after tBLA = 12 ns or tBLC = 15 ns.

Semaphore operation uses eight dedicated latches accessed via SEM pin activation; A0–A2 select latch index, and I/O0 controls token state (0 = acquired). Interrupts are generated by writes to mailbox addresses 1FFFH (right port) and 1FFEH (left port), with INT reset only upon owner-read - not cross-port read.

Key Specifications

Pinout & Package

Package: 84-pin Plastic Leaded Chip Carrier (PLCC), lead-free, body size 29.31 mm × 29.31 mm, 1.78 mm thickness, 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 IDT70V25L25PF, CY7C025-25JC provides integrated 5 V arbitration and semaphores - reducing BOM count and firmware complexity. Against CY7C028-25AC, it offers identical timing and logic but saves board area and cost where 8K × 16 suffices.

Availability

CY7C025-25JC is available at Aetrix Electronics and suitable for interprocessor communication, video frame buffering, telecom protocol stacking, and dual-core DSP co-processing requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for CY7C025-25JC 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 industrial, automotive, and communications infrastructure.

CY7C025 belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency interprocessor data exchange in real-time embedded systems.

FAQ

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

The M/S pin configures the device as master (M/S = HIGH) or slave (M/S = LOW) for bus-width expansion. In master mode, BUSY pins output arbitration status; in slave mode, they accept BUSY input from a master. This enables 32-/36-bit memory systems using multiple CY7C025 devices without external arbitration logic or discrete components.

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

The CY7C025-25JC contains eight dedicated semaphore latches accessed via SEM pin assertion. Writing 0 to a latch grants exclusive access to that resource; writing 1 releases it. Only the side holding the 0 can modify the latch. A0–A2 select the latch index, and I/O0 carries the token value - enabling hardware-enforced mutual exclusion without software polling overhead.

Can CY7C025-25JC operate at 3.3 V?

No. CY7C025-25JC is specified only for 5 V ±10% (4.5–5.5 V) operation. Its internal circuitry, including sense amplifiers and arbitration logic, is optimized for 5 V CMOS thresholds. Attempting 3.3 V operation results in undefined timing, failed arbitration, and potential data corruption - no 3.3 V variant exists in this family.

What happens when both ports attempt to write to the same address simultaneously?

On-address contention triggers on-chip arbitration: the port whose address arrives first (within tPS = 10 ns) gains access; the other port asserts BUSY. The winning port completes its write; the losing port's write is blocked until BUSY deasserts. No data corruption occurs, but firmware must poll BUSY and retry - guaranteed deterministic resolution only if tPS is met.