Infineon Technologies CY7C144-15AXCT

Overview

CY7C144-15AXCT from Cypress Semiconductor is an 8K × 8 true dual-port static RAM with independent left/right address, data, and control buses, 15 ns access time, TTL-compatible I/O, and integrated semaphore, interrupt, and busy arbitration logic. It enables simultaneous asynchronous read/write access to the same memory location in interprocessor communication and video buffering systems.

For engineers reviewing the CY7C144-15AXCT datasheet, CY7C144-15AXCT pinout, CY7C144-15AXCT application, or CY7C144-15AXCT equivalent, key selection criteria include dual-port arbitration behavior (BUSY/INT/SEM), master/slave expansion capability via M/S pin, 68-pin PLCC package compatibility, and industrial-grade standby current (ISB1 = 50 mA).

Technical Context

The CY7C144-15AXCT implements fully asynchronous dual-port architecture with separate CE/R/W/OE controls per port, enabling concurrent read/write operations without external synchronization. Its on-chip arbitration resolves contention via push-pull BUSY outputs (in master mode) and deterministic tPS-based priority timing.

Semaphore logic comprises eight dedicated latches accessed via SEML/SEMR and A0–A2, supporting software handshaking for shared resource management. Interrupt flags (INTL/INTR) are set/cleared by writes to fixed addresses (1FFE/1FFF) and operate as push-pull outputs requiring no pull-up resistors.

Key Specifications

Pinout & Package

Package: 68-pin Plastic Leaded Chip Carrier (PLCC), RoHS-compliant, body size 24.2 mm × 24.2 mm, 1.27 mm pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT71V256SA15YG and ISSI IS61WV102416BLL-15NLI, the CY7C144-15AXCT delivers integrated arbitration and resource management in a compact 68-pin PLCC, reducing BOM count and PCB area for tightly coupled dual-processor systems.

Availability

CY7C144-15AXCT is available at Aetrix Electronics and suitable for interprocessor communication, video frame buffering, communications protocol stack buffering, and industrial PLC data exchange requiring stable component supply across extended product lifecycles.

Supply support for CY7C144-15AXCT 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 logic solutions for industrial, automotive, and communications markets.

The CY7C144 series belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic, low-latency inter-processor data exchange in real-time embedded systems.

FAQ

What is the function of the M/S pin in CY7C144-15AXCT?

The M/S (Master/Slave Select) pin configures the device's BUSY signal behavior: when HIGH, BUSYL/BUSYR operate as push-pull outputs for master-mode arbitration signaling; when LOW, they become inputs for slave-mode daisy-chaining. This enables seamless 16-bit or wider memory expansion without external logic or matched device pairs, directly supporting bus-width scaling in multi-CPU architectures.

How do the semaphore latches operate in CY7C144-15AXCT?

The eight semaphore latches are accessed via SEML/SEMR and A0–A2, with I/O0 used for write data. Writing 0 to a semaphore grants exclusive access to that resource; reading returns the current state. The latch is owned by the side that first writes 0, and ownership transfers only after the current owner writes 1. Initialization requires writing 1 to all semaphores from both ports at power-up to ensure clean startup.

Can CY7C144-15AXCT operate with mixed voltage interfaces?

No - CY7C144-15AXCT is strictly 5 V ±10% compatible with TTL-level thresholds (VIH = 2.2 V, VIL = 0.8 V). It does not support mixed-voltage I/O or 3.3 V operation. Interfacing with lower-voltage controllers requires level-shifting circuitry, as the device lacks internal voltage translation or dual-supply capability.

What happens during simultaneous access to the same memory location?

When both ports assert CE and present matching addresses within tPS (15 ns), on-chip arbitration asserts BUSY on the losing port and grants access to the winning port. Data written by the winning port becomes visible to the losing port after tDDD (flowthrough delay). If tPS is violated, access is still granted to one port, but deterministic priority is not guaranteed - system firmware must poll BUSY to confirm readiness before proceeding.