Infineon Technologies CY7C007A-20JC

Overview

CY7C007A-20JC from Cypress Semiconductor is a 32K × 8 true dual-port static RAM with independent left/right ports, 20 ns access time, 5 V supply, and on-chip arbitration logic for interprocessor communication. It supports simultaneous read/write to the same memory location via BUSY flag signaling and includes semaphores and INT flags for software handshaking in real-time embedded systems.

For engineers reviewing the CY7C007A-20JC datasheet, CY7C007A-20JC pinout, CY7C007A-20JC application, or CY7C007A-20JC equivalent, key selection criteria include asynchronous dual-port timing, master/slave expandability, CMOS-level standby current (0.05 mA), and PLCC-68 packaging compatibility with legacy industrial control and video buffer designs.

Technical Context

The CY7C007A-20JC implements fully asynchronous dual-port architecture with separate address, data, and control buses per port (A0L–A14L/I/O0L–I/O7L/CEL/OEL/R/WL and A0R–A14R/I/O0R–I/O7R/CER/OER/R/WR). Arbitration is handled by on-chip logic that resolves contention within tPS (2 ns) using BUSYL/BUSYR flags, with deterministic resolution only when timing constraints are met.

It integrates eight dedicated semaphore latches accessible via SEML/SEMR pins, enabling resource locking between ports without external logic; interrupt generation uses upper two memory locations (7FFFH/7FFE H) as mailboxes, with INTL/INTR asserted on write and cleared on read by the owning port.

Key Specifications

Pinout & Package

68-pin Plastic Leaded Chip Carrier (PLCC) package with J-bend leads, body size 24.2 mm × 24.2 mm, compliant with JEDEC MS-026. Pin 1 index located at corner with notch marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT70V25L20PF and CY7C028V-20AC, the CY7C007A-20JC uniquely supports 5 V-only operation, PLCC-68 retrofit compatibility, and hardware-expandable word width via M/S pin - making it irreplaceable in legacy industrial upgrades where voltage, package, and expansion topology are fixed constraints.

Availability

CY7C007A-20JC is available at Aetrix Electronics and suitable for industrial PLC data exchange, video frame buffer sharing, and legacy test equipment memory expansion requiring stable component supply across extended production lifecycles.

Supply support for CY7C007A-20JC 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 CY7C007A belongs to Cypress's legacy dual-port SRAM product line, engineered specifically for deterministic interprocessor communication in real-time control systems where bus contention must be resolved in hardware.

FAQ

What is the function of the M/S pin on CY7C007A-20JC?

The M/S (Master/Slave) pin configures the device for word-width expansion: when HIGH, BUSYL/BUSYR become outputs for driving slave devices; when LOW, they act as inputs accepting arbitration signals from a master. This enables 16-bit or wider memory systems using multiple CY7C007A chips without external logic, preserving timing integrity across ports.

How does semaphore operation prevent resource conflicts between ports?

Semaphores use eight dedicated latches accessed via SEML/SEMR. Writing '0' to a latch claims a shared resource; reading back '0' confirms ownership. The latch remains locked until the owner writes '1'. This hardware-enforced mutual exclusion eliminates race conditions in multi-CPU firmware, unlike software-only flag polling which risks missed updates or deadlocks.

Can CY7C007A-20JC operate with only one port active?

Yes - each port operates independently. Disabling one port (e.g., holding CEL high) places it in CMOS-level standby (ISB3 = 0.05 mA), while the other port maintains full 20 ns access performance. This allows asymmetric usage in systems where one processor handles background tasks and the other manages real-time I/O, optimizing power without sacrificing responsiveness.

What happens during simultaneous access to the same memory location?

When both ports assert CE within tPS (2 ns) and target the same address, on-chip arbitration asserts BUSYL/BUSYR to indicate contention. The winning port gains immediate access; the losing port sees BUSY active and must retry. If tPS is violated, arbitration still occurs but the winner is unpredictable - firmware must implement BUSY polling loops to ensure deterministic behavior in all cases.