Infineon Technologies CY7C4231V-25AXCT

Overview

CY7C4231V-25AXCT from Cypress Semiconductor is a 2K × 9-bit synchronous FIFO memory with 3.3 V supply, 66 MHz max clock rate (25 ns cycle time), programmable Almost Empty/Almost Full flags, and dual-clock asynchronous read/write capability. It serves as a high-speed data buffer in multi-processor interconnects and serial communication interfaces requiring deterministic latency and flow control.

For engineers reviewing the CY7C4231V-25AXCT datasheet, CY7C4231V-25AXCT pinout, CY7C4231V-25AXCT application, or CY7C4231V-25AXCT equivalent, key selection criteria include its 2048-word depth, 9-bit bus width, 5 V-tolerant inputs, OE-controlled three-state outputs, and synchronous flag timing referenced to RCLK/WCLK edges.

Technical Context

The CY7C4231V-25AXCT implements a dual-port SRAM array with independent read and write pointers, controlled by separate RCLK and WCLK signals. Its flag logic is fully synchronous: EF and PAE update on RCLK edges; FF and PAF update on WCLK edges - eliminating metastability in clock-domain crossing scenarios.

It supports both single-clock (RCLK = WCLK) and true asynchronous operation. The WEN2/LD pin enables either dual-write-enable mode for depth expansion or flag-offset register programming (default empty/full offsets = 7 words), with offset values stored in four 8-bit registers accessible via WCLK/RCLK strobes under LD control.

Key Specifications

Pinout & Package

32-pin Thin Quad Flat Package (TQFP), 7 mm × 7 mm body, 0.8 mm pitch, lead-free (Pb-Free) compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FIFO buffering applications.

Compared with IDT72V2115L15PF and NB3N502MNR2G, the CY7C4231V-25AXCT uniquely combines pin-driven flag programming, 5 V-tolerant I/O, and center-ground layout - making it optimal for mixed-voltage, space-constrained designs requiring deterministic buffer control without external configuration hardware.

Availability

CY7C4231V-25AXCT is available at Aetrix Electronics and suitable for high-speed data acquisition, multi-processor interconnect, and serial communication interface applications requiring stable component supply across extended production lifecycles.

Supply support for CY7C4231V-25AXCT 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 fabless semiconductor company specializing in high-performance memory, microcontrollers, and programmable logic solutions for industrial and communications markets.

The CY7C42X1V series was designed specifically for deterministic, low-latency data buffering in mixed-clock-domain systems - emphasizing synchronous flag reliability, voltage flexibility, and board-level noise reduction.

FAQ

Is a power-on reset pulse required before using CY7C4231V-25AXCT?

Yes. An active-low RS pulse is mandatory after power stabilization to initialize internal pointers and guarantee EF = LOW. Without this reset, the FIFO may enter an undefined state, causing unpredictable read/write behavior or invalid flag outputs. The reset must meet tRS minimum pulse width and occur before any WCLK or RCLK activity.

Can CY7C4231V-25AXCT operate with RCLK and WCLK running at different frequencies?

Yes. The device supports fully asynchronous operation: RCLK and WCLK may run at independent frequencies up to 66 MHz each. EF and PAE are updated only on RCLK edges; FF and PAF only on WCLK edges - ensuring reliable flag synchronization without external clock-domain crossing logic.

What happens to Q0–Q8 outputs when OE is HIGH and the FIFO is not empty?

When OE is HIGH, all Q0–Q8 outputs enter high-impedance (Hi-Z) state regardless of FIFO content or RCLK activity. No data is driven onto the bus, enabling safe sharing with other devices. Outputs remain Hi-Z until OE returns LOW and a valid read cycle (REN1/REN2 LOW, EF = HIGH) occurs.

How is the default Almost Empty offset value of 7 words implemented in hardware?

The default value is hardwired into the empty offset LSB and MSB registers at mask level. During power-up reset, these registers load 007h (7 decimal). This value determines that PAE asserts LOW when ≤7 unread words remain - providing early warning before underflow while allowing sufficient margin for read latency.