50G Interlaken MegaCore Function User Guide

ID 683217
Date 9/20/2022
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

9.3. RX Out-of-Band Flow Control Signals

The receive out-of-band flow control interface receives input flow‑control clock, data, and sync signals and sends out calendar and status information. The RX Out-of-Band Flow Control Interface Signals table describes the receive out‑of‑band flow control interface signals specified in the Interlaken Protocol Specification, Revision 1.2. The RX Out-of-Band Flow Control Block Signals for Application Use describes the signals on the application side of the RX out‑of‑band flow control block.

Table 27.  RX Out-of-Band Flow Control Interface Signals

Signal Name

Direction

Width (Bits)

Description

fc_clk

Input

1

Input reference clock from an upstream out-of-band TX block. This signal clocks the fc_data and fc_sync signals. You must connect this signal to a device pin.

fc_data

Input

1

Input serial data pin from an upstream out-of-band TX block. You must connect this signal to a device pin.

fc_sync

Input

1

Input sync control pin from an upstream out-of-band TX block. You must connect this signal to a device pin.

Table 28.  RX Out-of-Band Flow Control Block Signals for Application Use

Signal Name

Direction

Width (Bits)

Description

sys_clk

Input

1

Reference clock for capturing RX calendar, lane status, and link status. Frequency must be at least double the frequency of the TX fc_clk input clock.

sys_arst

Input

1

Asynchronous reset for the out-of-band RX block.

status_update

Output

1

Indicates a new value without CRC4 errors is present on at least one of lane_status or link_status in the current sys_clk cycle. The value is ready to be read by the application logic.

lane_status

Output

Number of Lanes

Lane status bits received from an upstream out-of-band TX block on fc_data. Width is the number of lanes.

link_status

Output

1

Link status bit received from an upstream out-of-band TX block on fc_data.

status_error

Output

1

Indicates corrupt lane or link status. A new value is present on at least one of lane_status or link_status in the current sys_clk cycle, but the value has at least one CRC4 error.

calendar

Output

16

Calendar bits received from an upstream out-of-band TX block on fc_data.

calendar_update

Output

1

Indicates a new value without CRC4 errors is present on calendar in the current sys_clk cycle. The value is ready to be read by the application logic.

calendar_error

Output

1

Indicates corrupt calendar bits. A new value is present calendar in the current sys_clk cycle, but the value has at least one CRC4 error.