Infineon Technologies CY7C144-55JXCT

Overview

CY7C144-55JXCT from Cypress Semiconductor is an 8K × 8 true dual-port static RAM with independent left/right ports, 55 ns maximum access time, TTL-compatible I/O, and integrated semaphore, interrupt, and busy arbitration logic. It enables simultaneous asynchronous reads/writes to the same memory location in multiprocessor interconnects and video buffer applications.

For engineers reviewing the CY7C144-55JXCT datasheet, CY7C144-55JXCT pinout, CY7C144-55JXCT application, or CY7C144-55JXCT equivalent, key selection criteria include dual-port arbitration behavior, semaphore latch timing (tSOP, tSWRD), INT/ BUSY flag push-pull drive capability, and M/S-configurable master/slave bus expansion for 16-bit systems.

Technical Context

The CY7C144-55JXCT implements fully asynchronous dual-port architecture with separate CE/R/W/OE control per port, enabling concurrent read/write operations without external synchronization. Its on-chip arbitration uses address-match detection (tPS) and generates BUSY assertion (tBLA/tBLC) to resolve contention when both ports access identical addresses within 5 ns.

Semaphore logic consists of eight dedicated latches accessed via SEML/SEMR with A0–A2 addressing; writes use I/O0 only, and reads return latched values to prevent race conditions. INT flags operate as push-pull outputs-no pull-up required-and are set/cleared by port-specific write/read of fixed addresses (1FFE/1FFF), supporting mailbox-style interprocessor communication.

Key Specifications

Pinout & Package

Package: 68-pin PLCC (plastic leaded chip carrier), body size 24.2 mm × 24.2 mm, JEDEC MS-026AC compliant. Lead finish: Pb-free (RoHS-compliant).

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, the CY7C144-55JXCT delivers integrated hardware arbitration and semaphore logic in a 5 V, 64 Kbit package - reducing BOM count and firmware complexity for tightly coupled dual-processor systems.

Availability

CY7C144-55JXCT is available at Aetrix Electronics and suitable for interprocessor communication buffers, video frame buffers, industrial PLC I/O mapping, and communications protocol stack buffers requiring stable component supply and long-term industrial temperature support (–40°C to +85°C).

Supply support for CY7C144-55JXCT 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 solutions for industrial, automotive, and communications infrastructure markets.

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

FAQ

What is the function of the M/S pin on CY7C144-55JXCT?

The M/S (Master/Slave Select) pin configures the device's BUSY pin behavior: when HIGH, BUSYL/BUSYR operate as push-pull outputs for master-mode arbitration; when LOW, they become inputs for slave-mode operation, allowing daisy-chained multi-device bus expansion. This eliminates external logic for 16-bit+ memory width implementations.

How does semaphore arbitration work without external clocks?

Semaphore access is fully asynchronous and controlled by SEML/SEMR assertion. Writing a 0 to a semaphore latch (via I/O0L/I/O0R with A0–A2 selecting the latch) grants exclusive ownership; reading returns the latched value. No clock is required - timing relies solely on tSOP (semaphore operation pulse width) and tSWRD (write-to-read delay) specifications.

Can INTL and INTR be used simultaneously for bidirectional messaging?

Yes: INTL is asserted when the right port writes to address 1FFE and cleared when the left port reads it; INTR is asserted when the left port writes to 1FFF and cleared when the right port reads it. This enables full-duplex mailbox communication - each port has its own dedicated interrupt flag and message address.

What happens during simultaneous access to the same memory location?

When both ports assert CE and present matching addresses within tPS (5 ns), on-chip logic asserts BUSYL/BUSYR to indicate contention. The winning port gains access; the losing port sees BUSY HIGH and must retry. Data integrity is preserved - no bus conflict or corruption occurs, and tDDD (data flowthrough delay) ensures deterministic read timing after cross-port writes.