Infineon Technologies CY7C144-15JXI

Overview

CY7C144-15JXI 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 multiprocessor interconnect, video frame buffering, and communications status sharing applications.

For engineers reviewing the CY7C144-15JXI datasheet, CY7C144-15JXI pinout, CY7C144-15JXI application, or CY7C144-15JXI equivalent, key selection criteria include dual-port arbitration behavior (BUSY/INT/SEM timing), master/slave expansion capability via M/S pin, 68-pin PLCC package compatibility, and industrial temperature support (–40°C to +85°C).

Technical Context

The CY7C144-15JXI implements fully asynchronous dual-port operation with separate CE/R/W/OE controls per port, enabling concurrent reads or writes without external synchronization. Its on-chip arbitration resolves contention via push-pull BUSY outputs (in master mode) with tBLA = 8 ns assertion delay and tBLC = 10 ns response after CE deassertion.

Semaphore logic uses eight shared latches accessed via SEML/SEMR and A0–A2, requiring tSOP = 20 ns between SEM deassertion and read, with tSWRD + tDOE = 15 ns latency for semaphore value availability. INT flags are set by writes to fixed addresses (1FFE/1FFF) and cleared by corresponding reads - both INTL and INTR are push-pull outputs needing no pull-up resistors.

Key Specifications

Pinout & Package

Package: 68-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-026AC compliant, lead-free (Pb-free) option available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V25L15PF, CY7C144-15JXI provides on-chip semaphore and M/S expansion - reducing BOM count and PCB area. Versus CY7C146-15JXI, it offers cost-optimized 8-bit data path without parity overhead, ideal for bandwidth-constrained control applications.

Availability

CY7C144-15JXI is available at Aetrix Electronics and suitable for interprocessor communication buffers, video frame memory sharing, telecom protocol stack buffers, and industrial PLC data exchange requiring stable component supply across extended temperature ranges.

Supply support for CY7C144-15JXI 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 markets.

CY7C144 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 CY7C144-15JXI?

The M/S pin configures the device as master (M/S = HIGH) or slave (M/S = LOW). In master mode, BUSYL and BUSYR are push-pull outputs signaling arbitration outcomes; in slave mode, they become inputs accepting BUSY signals from a master device. This enables seamless 16/18-bit memory expansion without external logic or discrete master/slave pairing.

How does semaphore arbitration work between ports?

Semaphores are eight shared latches accessed via SEML/SEMR and A0–A2. A port gains ownership by writing 0 to a semaphore address; reading back 0 confirms acquisition. The latch remains locked until the owning port writes 1. Both ports can read the current state, but only the owner may modify it - preventing race conditions in resource allocation.

Can INTL and INTR be used simultaneously for bidirectional messaging?

Yes. INTL is set when the right port writes to address 1FFE and cleared when the left port reads it; INTR is set by left-port write to 1FFF and cleared by right-port read. These independent flags enable full-duplex mailbox communication - e.g., left port signals "data ready" via 1FFF while right port signals "buffer free" via 1FFE.

What is the minimum pulse width requirement for CE, OE, and R/W signals?

Per datasheet timing diagrams, CE and OE must remain stable for ≥5 ns before and after R/W transitions. R/W pulse width must be ≥10 ns (for 15 ns speed grade). Violating these causes undefined behavior - especially during semaphore or interrupt operations where tSD (setup time) and tHZWE (write hold) are strictly enforced.