Infineon Technologies CY7C144-55JXC

Overview

CY7C144-55JXC from Cypress Semiconductor is an 8K × 8 true dual-port static RAM with independent left/right address, data, and control buses, 55 ns maximum access time, TTL-compatible I/O, and integrated semaphore/INT/BUSY arbitration logic for multiprocessor intercommunication. It operates at 5 V ±10% across commercial temperature range (0°C to +70°C) and is used in interprocessor buffering, video frame memory, and real-time communications controllers.

For engineers reviewing the CY7C144-55JXC datasheet, CY7C144-55JXC pinout, CY7C144-55JXC application, or CY7C144-55JXC equivalent, key selection criteria include dual-port contention resolution timing (tPS = 15 ns), semaphore latch behavior (8 shared latches, A0–A2 address mapping), INT flag mailbox addressing (1FFE/1FFF), M/S master/slave expansion capability, and 68-pin PLCC package mechanical compatibility.

Technical Context

The CY7C144-55JXC implements fully asynchronous dual-port operation with separate CE/R/W/OE controls per port, enabling concurrent read/write access to any memory location. Its on-chip arbitration uses BUSY flags (push-pull, no pull-up required) and tPS-based priority resolution to manage simultaneous access conflicts.

Interrupt signaling operates via dedicated INTL/INTR pins tied to fixed addresses (1FFE and 1FFF), supporting mailbox-style port-to-port communication. Semaphore logic comprises eight independent latches accessed via SEML/SEMR with A0–A2 addressing, where write-0 grants exclusive resource ownership and read-back validates acquisition - all requiring tSOP deassertion delay before verification.

Key Specifications

Pinout & Package

Package: 68-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-026AC compliant, body size 24.2 mm × 24.2 mm, lead pitch 0.05 inch, RoHS-compliant Pb-free finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V25L25PF and IS61LV5128AL-15TQLI, CY7C144-55JXC delivers integrated hardware arbitration and interprocessor signaling in a single 5 V device - reducing PCB area, eliminating timing-critical external logic, and simplifying firmware development for tightly coupled multiprocessing.

Availability

CY7C144-55JXC is available at Aetrix Electronics and suitable for interprocessor communication buffers, dual-port video frame memory, and real-time communications controllers requiring stable component supply and long-term industrial availability.

Supply support for CY7C144-55JXC 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 mixed-signal ICs for industrial, automotive, and communications infrastructure applications.

CY7C144 belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic multiprocessor memory sharing with minimal external components and guaranteed arbitration behavior.

FAQ

What is the function of the M/S pin in CY7C144-55JXC?

The M/S (Master/Slave Select) pin configures the device for bus-width expansion: when HIGH, it operates as a master with BUSY pins as outputs; when LOW, as a slave with BUSY pins as inputs. This enables daisy-chained 16/18-bit memory systems without external logic, using the master's BUSY signal to gate slave access timing.

How do the semaphore latches operate in CY7C144-55JXC?

The eight semaphore latches are accessed via SEML/SEMR with A0–A2 selecting the latch; writing 0 to I/O0 acquires ownership, reading returns the current state. Acquisition is atomic and exclusive - only the side that successfully writes 0 can modify the latch until it writes 1 to release. Initialization requires writing 1 to all semaphores at power-up from both ports.

Can CY7C144-55JXC support simultaneous read and write to the same address?

Yes, but with controlled arbitration: if both ports access the same address within tPS (15 ns), BUSY asserts to indicate contention, and the internal logic grants access to one port deterministically. The ungranted port sees BUSY high and must retry; no data corruption occurs, and the granted port completes its operation normally.

What are the voltage and timing requirements for reliable INT flag operation?

INTL and INTR are push-pull outputs requiring no pull-up; they assert when the opposite port writes to 1FFE (INTL) or 1FFF (INTR), and clear upon local read of that address. Valid operation requires VCC = 5 V ±10%, and address setup/hold times per Table 4 - specifically, CE and R/W must meet tAS/tAH relative to address assertion for reliable flag setting.