Infineon Technologies CY7C131-25JXC

Overview

CY7C131-25JXC 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 - used in multi-processor cache buffers and DSP shared-memory systems.

For engineers reviewing the CY7C131-25JXC datasheet, CY7C131-25JXC pinout, CY7C131-25JXC application, or CY7C131-25JXC equivalent, key selection criteria include dual-port arbitration timing (tBLA ≤20 ns), standby current (ISB1 = 65 mA max), 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 separate CE/R/W/OE controls 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 deterministic inter-port communication.

It supports automatic power-down per port via CE assertion and delivers guaranteed 25 ns read cycle time (tRC) under commercial temperature range (0°C to +70°C) with 5 V ±10% supply. Open-drain BUSY outputs require external pull-up resistors; all I/Os are TTL-compatible with VIH ≥2.2 V and VOL ≤0.4 V at 4 mA.

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-026AC compliant, lead-free (Pb-free) variant available. Pin layout optimized for dual-port signal separation with dedicated address/data/control banks per port and symmetrical power/ground distribution.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C131-25ZXC, the JXC variant offers through-hole PLCC mounting for prototyping and legacy repair; versus CY7C141-25JXC, it provides full standalone functionality with autonomous BUSY arbitration - critical for asymmetric multi-processor topologies.

Availability

CY7C131-25JXC is available at Aetrix Electronics and suitable for DSP shared-memory buffers, multi-processor cache coherence systems, and bit-slice processor interconnects requiring stable component supply and long-term obsolescence management.

Supply support for CY7C131-25JXC 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 solutions for industrial, automotive, and communications markets.

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

FAQ

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

BUSYL and BUSYR are open-drain outputs that assert LOW when their respective port attempts to access an address currently being accessed by the opposite port. This signal requires an external pull-up resistor (typically 4.7 kΩ to VCC) and enables hardware-level arbitration without CPU intervention. Timing is guaranteed ≤20 ns from address match (tBLA).

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

No. CY7C131-25JXC is specified only for 5 V ±10% (4.5–5.5 V) operation. Its input thresholds (VIH ≥2.2 V, VIL ≤0.8 V) and output drive levels (VOH ≥2.4 V @ –4 mA) are TTL-compatible and incompatible with 3.3 V logic families without level-shifting circuitry.

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

INTL and INTR are open-drain interrupt flags that assert LOW when a write occurs to fixed addresses: 3FFH triggers INTL, 3FEH triggers INTR. These locations are reserved exclusively for interrupt generation and do not store user data. The flag remains asserted until cleared by a read from the same address, enabling edge-triggered or level-sensitive handshaking.

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

No. CY7C131-25JXC uses a 52-pin PLCC package, while CY7C130-25JXC is offered only in 48-pin DIP. Although functional behavior is identical, the pin count, layout, and mechanical footprint differ - requiring distinct PCB footprints and socketing solutions.