Infineon Technologies CY7C4235-15AXCT

Overview

CY7C4235-15AXCT from Cypress Semiconductor is a 2K × 18-bit synchronous FIFO memory with TTL-compatible interfaces, 10 ns read/write cycle time, and programmable Almost Empty/Almost Full flags. It supports independent 100 MHz read/write clocks, retransmit functionality, and depth/width expansion for buffering in high-speed data acquisition and multiprocessor interconnects.

For engineers reviewing the CY7C4235-15AXCT datasheet, CY7C4235-15AXCT pinout, CY7C4235-15AXCT application, or CY7C4235-15AXCT equivalent, key selection criteria include its 2048-word depth, 18-bit bus width, synchronous flag timing control via VCC/SMODE, and cascading capability using WXO/RXO/FL pins.

Technical Context

The CY7C4235-15AXCT implements a dual-port SRAM array with independent read and write pointers, controlled by asynchronous RCLK/WCLK inputs. Its flag logic delivers five synchronized status outputs (EF, FF, PAE, PAF, HF), where EF and FF are strictly clock-synchronized to RCLK and WCLK respectively.

Programmable offset registers (12-bit) allow user-defined Almost Empty/Almost Full thresholds; configuration occurs via LD/WEN-controlled write sequences on WCLK edges. Retransmit (RT) resets the read pointer to enable packet-level data replay without external controller intervention.

Key Specifications

Pinout & Package

Package: 64-pin TQFP (10 mm × 10 mm, 0.5 mm pitch) - surface-mount compatible with automated PCB assembly and thermal performance suited for industrial temperature operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IDT72225L15PF and SN74V293-15PAG, the CY7C4235-15AXCT uniquely integrates retransmit capability and dual-mode flag synchronization (via VCC/SMODE), enabling hardware-accelerated packet recovery and flexible timing integration not available in either alternative.

Availability

CY7C4235-15AXCT is available at Aetrix Electronics and suitable for high-speed data acquisition, multiprocessor interconnect, serial protocol bridging, and test equipment pattern buffering requiring stable component supply across industrial temperature ranges.

Supply support for CY7C4235-15AXCT 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-performance memory and programmable logic solutions for industrial, automotive, and communications systems.

The CY7C42X5 family was engineered specifically for deterministic, low-latency data buffering in asynchronous clock domain crossings - emphasizing pin-compatible scalability and hardware-managed flow control.

FAQ

What is the default Almost Empty offset value for CY7C4235-15AXCT?

The default Almost Empty offset is 127 words. This value is stored in the internal 12-bit offset register and causes the PAE flag to assert when 127 or fewer words remain in the FIFO. It can be reprogrammed using the LD/WEN/WCLK sequence described in the functional specification, and remains persistent until rewritten.

Can CY7C4235-15AXCT operate with a single clock for both read and write?

Yes - RCLK and WCLK may be tied together for single-clock operation. In this mode, the device functions as a synchronous FIFO with shared timing, retaining all status flag behavior and retransmit capability. The 10 ns cycle time applies to the combined clock, and EF/FF remain synchronized to that clock edge.

How does the FL/RT pin behave in standalone versus cascaded configurations?

In standalone mode, FL/RT operates exclusively as Retransmit (RT): a HIGH pulse resets the read pointer. In cascaded depth expansion, FL/RT serves as First Load (FL): the first device has FL tied to VSS, others to VCC - enabling proper pointer initialization across the chain. The pin's dual function is determined by system wiring, not internal configuration.

Is the Half Full (HF) flag available when using width expansion?

Yes - the WXO/HF pin retains Half Full functionality in standalone and width-expansion configurations. In depth expansion, WXO/HF becomes the Write Expansion Out signal and HF indication is disabled. Width expansion (parallel 18-bit → 36-bit) preserves all five status flags on each device, allowing independent monitoring per lane.