Infineon Technologies CY7C131-25NXC

Overview

CY7C131-25NXC from Cypress Semiconductor is a 1 K × 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 and features BUSY arbitration and INT port-to-port interrupt flags for multi-processor cache and DSP buffer applications.

For engineers reviewing the CY7C131-25NXC datasheet, CY7C131-25NXC pinout, CY7C131-25NXC application, or CY7C131-25NXC equivalent, key selection criteria include dual-port arbitration timing (tBLA = 20 ns), standby current (ISB1 = 65 mA), open-drain BUSY output requiring pull-up, and compatibility with CY7C141 slave devices for 16-bit expansion.

Technical Context

The CY7C131-25NXC implements fully asynchronous dual-port operation with independent CE, R/W, and OE controls per port, enabling concurrent read/write access to shared memory without external arbitration logic. Its on-chip arbitration logic resolves contention via open-drain BUSY outputs and priority-based port access.

It integrates dedicated interrupt flag registers at addresses 3FFH (left port) and 3FEH (right port), with programmable set/reset timing (tWINS = 25 ns, tOINR = 25 ns). Automatic power-down is controlled per port via CE, supporting ISB3 = 15 mA CMOS-input standby mode.

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), lead-free, RoHS-compliant, body size 19.1 mm × 19.1 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C131-30NXC, the -25NXC delivers 5 ns faster access for tighter timing margins in high-speed DSP; versus CY7C141-25NXC, it operates autonomously as a master device with full arbitration logic, eliminating dependency on external master control.

Availability

CY7C131-25NXC is available at Aetrix Electronics and suitable for DSP cache memory, multi-processor shared buffers, and bit-slice processor interconnects requiring stable component supply and long-term industrial lifecycle support.

Supply support for CY7C131-25NXC 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 solutions for industrial and embedded systems.

The CY7C131 series belongs to Cypress's dual-port SRAM product line, designed specifically for deterministic, low-latency shared memory in multi-processor, DSP, and real-time control applications.

FAQ

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

The BUSY pin is an open-drain output that asserts low when its port attempts to access a memory location currently being accessed by the opposite port. It requires an external pull-up resistor and provides hardware-level arbitration feedback with 20 ns response time (tBLA), enabling immediate stall or retry handling in real-time systems without software polling.

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

No. The CY7C131-25NXC is specified only for 5 V ±10% operation (4.5 V to 5.5 V). Its input thresholds (VIH = 2.2 V, VIL = 0.8 V) and output drive levels (VOH = 2.4 V, VOL = 0.4 V) are designed for TTL/5 V CMOS compatibility. Using 3.3 V violates absolute maximum ratings and will result in undefined behavior or permanent damage.

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

The INT flag is asserted when data is written to dedicated addresses: 3FFH triggers INTL, and 3FEH triggers INTR. These are edge-triggered, latched signals reset by reading the respective address. With tWINS = 25 ns setup and tOINR = 25 ns reset timing, they enable reliable hardware handshaking between asynchronous processors without shared clocks or additional control lines.

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

No. CY7C131-25NXC uses a 52-pin PLCC package, while CY7C130-25NXC is only available in 48-pin DIP. Although functional equivalence exists between CY7C130/CY7C131 families, the physical packages differ entirely-no mechanical or solder footprint compatibility exists between these variants.