Infineon Technologies CY7C131-25JC

Overview

CY7C131-25JC from Cypress Semiconductor is a 1K × 8 true dual-port static RAM with independent left/right ports, 25 ns maximum access time, 5 V ±10% supply, and 52-pin PLCC package. It supports simultaneous reads of the same memory location, features BUSY arbitration logic and INT interrupt flags, and serves as a master device in 16-bit+ bus expansion systems with CY7C141 slaves.

For engineers reviewing the CY7C131-25JC datasheet, CY7C131-25JC pinout, CY7C131-25JC application, or CY7C131-25JC equivalent, key selection criteria include dual-port arbitration timing (tBLA = 20 ns), port-isolated power-down control, open-drain BUSY output requiring pull-up, and compatibility with IDT7130-based designs in multiprocessor cache and DSP buffer applications.

Technical Context

The CY7C131-25JC implements fully asynchronous dual-port SRAM architecture with separate address, data, and control buses per port (A0L–A9L/I/O0L–I/O7L/CEL/OEL/R/WL and A0R–A9R/I/O0R–I/O7R/CER/OER/R/WR). Arbitration logic resolves contention via open-drain BUSYL/BUSYR signals, while dedicated INTL/INTR flags enable inter-port communication at fixed addresses (3FFh/3FEh).

It supports three standby modes: both ports disabled (ISB1 = 65 mA max), one port active (ISB2 = 115 mA max), and CMOS-input deep sleep (ISB3 = 15 mA max). The 0.65 µm CMOS process enables 25 ns read cycle time (tRC) with tDOE = 15 ns and tHZOE = 15 ns, meeting industrial temperature range (–40°C to +85°C) operation at 5 V.

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-026AC compliant, surface-mount compatible with reflow profiles for industrial PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT7130LA25JG, CY7C131-25JC provides integrated hardware arbitration eliminating external logic, while versus CY7C131-25JI it offers proven thermal cycling reliability in PLCC sockets for field-serviceable industrial modules.

Availability

CY7C131-25JC is available at Aetrix Electronics and suitable for DSP cache memory, bit-slice processor buffers, and multiprocessor shared memory systems requiring stable component supply across extended product lifecycles.

Supply support for CY7C131-25JC 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) is a fabless semiconductor company specializing in high-performance memory, PSoC, and USB solutions for industrial and automotive markets.

The CY7C131 belongs to Cypress's legacy dual-port SRAM product line, designed specifically for deterministic, low-latency inter-processor communication in real-time embedded systems where software-managed coherence is impractical.

FAQ

What is the function of the BUSY pin on CY7C131-25JC?

The BUSY pin is an open-drain output that asserts low when the local port attempts to access a memory location currently being accessed by the opposite port. It requires an external pull-up resistor (typically 4.7 kΩ to VCC) and responds within 20 ns (tBLA) to resolve contention - enabling external logic to stall the conflicting access before data corruption occurs.

Can CY7C131-25JC operate with a 3.3 V supply?

No. CY7C131-25JC is specified only for 5 V ±10% (4.5 V to 5.5 V) operation. Its input thresholds (VIH = 2.2 V, VIL = 0.8 V) and output drive strength (IOH/IOL) are optimized for 5 V TTL/CMOS interfaces. Using 3.3 V violates absolute maximum ratings and will cause functional failure or accelerated wear-out.

How does the INT flag work in inter-port communication?

INTL and INTR are dedicated interrupt flags tied to fixed addresses: writing to address 3FFh (left port) sets INTR, and writing to 3FEh (right port) sets INTL. Each flag remains asserted until cleared by reading its respective address - enabling zero-overhead handshaking without polling or shared registers.

Is CY7C131-25JC pin-compatible with CY7C130-25JC?

Yes, both share identical 52-pin PLCC pinouts and signal assignments. However, CY7C130-25JC is rated for commercial temperature range (0°C to +70°C), while CY7C131-25JC supports industrial range (–40°C to +85°C) - making the latter suitable for harsh environments but electrically interchangeable in controlled settings.