1 Features

1• Supports Control Signal Management and I2C

Aggregation Across Four Ports

• Combine Multiple FPC401s to Control 56 Total

Ports Through a Single Host Interface

• Eliminates Need for Discrete I2C Muxes, LED

Drivers, and High-Pin-Count FPGA/CPLD Control

Devices

• Reduces PCB Routing Complexity by Handling All

Low-Speed Control Signals Close to the Port

• Selectable I2C (Up to 1 MHz) or SPI (Up to 10

MHz) Host Control Interface

• Automatic Pre-Fetching of Critical, User-Specified

Data From the Modules

• Low Single-Port and Multi-Port Read/Write

Latency: <50 μs for SPI Mode, <400 μs for I2C

Mode

• Broadcast Mode Allows Writes to All Ports

Simultaneously Across All FPC401 Controllers

• Advanced LED Features for Port Status

Indication, Including Programmable Blinking and

Dimming

• Customizable Interrupt Events

• Separate Host-Side I/O Voltage: 1.8-V to 3.3-V

• Small QFN Package Enabling Placement on

Bottom Side of PCB Underneath Ports

2 Applications

• ToR/Aggregation/Core Switch and Router

SFP+/QSFP+ Port Control

• SAS External Cable Management Interface

Control

• Video Switch & Router SFP+/QSFP+ Port Control

3 Description

The FPC401 quad port controller serves as a lowspeed

signal aggregator for common port types such

as SFP+, QSFP+, and SAS. The FPC401 aggregates

all low-speed control and I2C signals across four

ports and presents a single easy-to-use management

interface to the host (I2C or SPI). Multiple FPC401s

can be used in high-port-count applications with one

common control interface to the host. The FPC401 is

designed to allow placement on the bottom side of

the PCB, underneath the press fit connector, to

simplify routing. This localized control of the ports’

low-speed signals cuts system BOM cost by enabling

the use of smaller IO count control devices (FPGAs,

CPLDs, MCUs) and by reducing routing layer

congestion.