Infineon Technologies CY7C136-55NXCT

Overview

CY7C136-55NXCT from Cypress Semiconductor is a 2K × 8 true dual-port static RAM with independent left/right ports, 55 ns maximum access time, 5 V supply, and 52-pin PLCC package. It enables simultaneous read access to the same memory location and supports master-mode arbitration in 16-bit+ bus expansion systems using CY7C142/CY7C146 slave devices. Used in DSP cache, multiprocessor interconnect, and bit-slice architectures.

For engineers reviewing the CY7C136-55NXCT datasheet, CY7C136-55NXCT pinout, CY7C136-55NXCT application, or CY7C136-55NXCT equivalent, key selection criteria include BUSY/INT flag timing (tBLA = 20 ns, tWINS = 25 ns), asymmetric standby current (ISB2 = 75 mA), open-drain BUSY output requiring pull-up, and 52-pin PLCC mechanical compatibility with CY7C136A-55NXCT.

Technical Context

This device implements fully asynchronous dual-port SRAM architecture with separate address, data, and control buses per port (A0L–A10L/I/O0L–I/O7L/CEL/OEL/R/WL/BUSYL/INTL and A0R–A10R/I/O0R–I/O7R/CER/OER/R/WR/BUSYR/INTR). Arbitration logic resolves contention when both ports access the same address, asserting BUSY on the lower-priority port.

The 52-pin PLCC version includes dedicated INT pins for port-to-port communication via fixed interrupt locations (7FF_H for left port, 7FE_H for right port) and supports automatic power-down per port via CE-driven control. BUSY outputs are open-drain and require external pull-up resistors; all timing parameters referenced to 1.5 V thresholds with 30 pF load.

Key Specifications

Pinout & Package

Package: 52-pin Plastic Leaded Chip Carrier (PLCC), JEDEC MS-018AC, body size 19.13 mm × 19.13 mm, lead pitch 0.5 mm, RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY7C136A-55NXCT, the original CY7C136-55NXCT offers identical functionality but may have shorter remaining production lifetime; versus CY7C146-55NXCT, it provides full master capability including arbitration and interrupt generation-making it suitable for standalone dual-processor designs without external coordination logic.

Availability

CY7C136-55NXCT is available at Aetrix Electronics and suitable for DSP cache memory, multiprocessor interconnect, and bit-slice processor systems requiring stable component supply across extended industrial temperature ranges and long product lifecycles.

Supply support for CY7C136-55NXCT 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 logic solutions for industrial, automotive, and communications markets.

CY7C136 belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for high-reliability, low-latency shared-memory applications in multiprocessor, DSP, and bit-slice computing architectures.

FAQ

What is the function of the BUSY pin on CY7C136-55NXCT?

The BUSY pin is an open-drain output that asserts LOW when the associated port attempts to access a memory location currently being accessed by the opposite port. It signals arbitration conflict and must be pulled up externally to VCC. This enables hardware stall insertion in CPU or DMA controllers to prevent data corruption during simultaneous access.

Can CY7C136-55NXCT operate with only one port enabled?

Yes-each port operates independently. Disabling one port via its CE pin places it in automatic power-down mode (ISB2 = 75 mA), while the other port remains fully functional with full-speed access. This is commonly used in asymmetric multiprocessing where one CPU handles real-time tasks and the other performs background processing.

How does the INT pin work in CY7C136-55NXCT?

The INT pin is an open-drain interrupt flag that goes LOW when data is written to its dedicated address (7FF_H for left port, 7FE_H for right port). It remains asserted until the corresponding port reads from that address, providing hardware-level interprocessor signaling without software polling or timer overhead.

Is CY7C136-55NXCT pin-compatible with CY7C136A-55NXCT?

Yes-CY7C136-55NXCT and CY7C136A-55NXCT share identical pinout, timing, and electrical specifications per Cypress documentation. The "A" suffix denotes an enhanced manufacturing revision with improved process yield and extended product longevity, but no functional or mechanical differences exist for system design or PCB layout.