Dual Port Controller With Expanded I/Os

The FPC202 dual port controller serves

as a low-speed signal aggregator for common port types such as SFP, QSFP, Mini-SAS

HD, and others. The FPC202 aggregates all low-speed control and I2C signals across

two ports and presents a single easy-to-use management interface to the host (I2C or

SPI). Multiple FPC202s can be used in high-port-count applications with one common

control interface to the host.

The FPC202

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 bill of materials (BOM) cost by enabling the use of smaller I/O

count control devices (FPGAs, CPLDs, MCUs) and by reducing routing layer

congestion.

The FPC202 is compatible with standard

SFF-8431, SFF-8436, and SFF-8449 low-speed management interfaces, including a

dedicated 100/400-kHz I2C interface to each port. Additional general-purpose pins

are available to perform functions such as driving port status LEDs or controlling

power switches. The LED drivers have convenience features such as programmable

blinking and dimming. The interface to the host controller can operate on a separate

supply voltage between 1.8 V and 3.3 V to support low-voltage I/Os.

For each port, the FPC202 has a total

of four LED drivers, 12 general-purpose I/Os, and two downstream I2C busses. This

expanded set of I/Os allows for control of additional components and features within

a system. The general-purpose outputs can be used to drive additional LEDs if more

than four are required per port.

The FPC202 can pre-fetch data from

user-specified registers in each module, making the data readily accessible to the

host through a fast I2C (up to 1 MHz) or SPI (up to 10 MHz) interface. In addition,

the FPC202 can trigger an interrupt to the host whenever critical, user-configurable

events occur associated with any of the ports under its control. This eliminates the

need to continuously poll the modules.