Infineon Technologies CY7C131-55NXC

Overview

CY7C131-55NXC from Cypress Semiconductor is a 1 K × 8 true dual-port static RAM with independent left/right ports, 55 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. Used in multi-processor cache buffers and DSP shared-memory subsystems.

For engineers reviewing the CY7C131-55NXC datasheet, CY7C131-55NXC pinout, CY7C131-55NXC application, or CY7C131-55NXC equivalent, key selection criteria include dual-port arbitration timing (tBLA ≤20 ns), standby current (ISB1 = 35 mA), open-drain BUSY output requiring external pull-up, and compatibility with CY7C141 for 16-bit bus expansion.

Technical Context

This device implements fully asynchronous dual-port SRAM architecture with independent CE/R/W/OE control per port and hardware-based arbitration logic that asserts BUSY when both ports attempt concurrent access to the same address. The INT flag uses fixed-location signaling (3FFH left, 3FEH right) for inter-port data notification.

It supports automatic power-down per port via CE assertion and operates across commercial (0°C to +70°C) and industrial (–40°C to +85°C) temperature ranges. The 0.65 µm CMOS process enables low-power operation while maintaining deterministic timing at 55 ns access.

Key Specifications

Pinout & Package

52-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead configuration, body size 19.1 mm × 19.1 mm, lead pitch 0.5 mm. RoHS-compliant (Pb-free) variant confirmed in ordering code suffix "NXC".

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C131-45NXC, the -55NXC trades 10 ns speed for lower dynamic power and relaxed timing closure; versus CY7C141-55NXC, it provides full master functionality including autonomous BUSY arbitration and INT flag generation-making it self-contained for dual-processor designs.

Availability

CY7C131-55NXC is available at Aetrix Electronics and suitable for DSP shared-memory buffers, multi-processor cache coherency modules, and industrial motion controller data buffering requiring stable component supply across commercial and industrial temperature grades.

Supply support for CY7C131-55NXC 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 memory, microcontrollers, and programmable system-on-chip solutions for embedded and industrial applications.

The CY7C13x series was designed specifically for deterministic, low-latency shared-memory interconnect in real-time multi-processor and digital signal processing systems-prioritizing arbitration reliability over density or cost.

FAQ

What is the function of the BUSY pin on CY7C131-55NXC?

The BUSY pin is an open-drain output that asserts low when both ports attempt to access the same memory address simultaneously. It requires an external pull-up resistor and provides hardware-level arbitration feedback within ≤20 ns (tBLA), enabling immediate stall or retry handling without software polling.

Can CY7C131-55NXC operate at 3.3 V?

No. CY7C131-55NXC is specified only for 5 V ±10% operation (4.5–5.5 V). Its VIH minimum is 2.2 V and VOL maximum is 0.4 V at 4 mA, which aligns with TTL/5 V CMOS logic families-not 3.3 V LVTTL or LVCMOS. Attempting 3.3 V supply risks functional failure and violates absolute maximum ratings.

How does the INT flag work in practice?

The INT flag is asserted when either port writes data to dedicated addresses: 3FFH (left port INT) or 3FEH (right port INT). This triggers an open-drain interrupt signal used for zero-latency inter-port handshaking. The flag clears automatically upon reading the addressed location, enabling simple producer-consumer protocols without additional control registers.

Is CY7C131-55NXC pin-compatible with CY7C130-55NXC?

No. CY7C131-55NXC uses a 52-pin PLCC package, while CY7C130-55NXC uses a 48-pin DIP package. Though functionally identical (same pin functions and timing), the physical pin count, layout, and package type differ-requiring separate PCB footprints and assembly tooling. Migration necessitates board redesign.