Agilex™ 7 M-Series FPGA Network-on-Chip (NoC) User Guide

ID 768844
Date 9/30/2024
Public
Document Table of Contents

2.3. NoC Switch and Link Detail

The NoC segment diagrams in the NoC Segments section show a simplified view of the switches and high-speed links that comprise the hard memory NoC. To simplify the explanation, these diagrams show the high-speed links as a single, bidirectional bus connecting the switch network.

However, the single bidirectional link in these diagrams actually represent four, high-speed links:

  • Two links (LR0 and LR1) carry traffic left-to-right.
  • The other two links (RL0 and RL1) carry traffic right-to-left.

Each of the NoC initiator bridges connect with all four high-speed links. However, the NoC target bridges connect to only two of the links, one in each direction. The target connections alternate:

  • One NoC target bridge connects to LR0 and RL0.
  • The adjacent NoC target bridge connects to LR1 and RL1.

Refer to Figure 13. Horizontal Link Allocation for Top-Edge NoC and Figure 14. Horizontal Link Allocation for Bottom-Edge NoC for NoC target bridge link connection details.

Additionally, the switches in the NoC Segments section diagrams represent multiple switches to connect to each of the horizontal links. Again, the NoC initiator bridges can connect to all four of the horizontal links, while the NoC target bridges connect to only two horizontal links, one in each direction. Additionally, each NoC initiator bridge has local connections to up to two NoC target bridges. These connections are known as “local” because they do not use the horizontal links at all.

Figure 8. Example NoC Initiator Bridge Connectivity shows example connectivity for a NoC initiator bridge. This bridge connects to all four of the horizontal links. This bridge also connects to one NoC target bridge through a local connection without using the horizontal link. For simplicity, additional target bridge connections do not appear.

Figure 8. Example NoC Initiator Bridge Connectivity


Figure 9. Example NoC Target Bridge Connectivity with Local Connection to One NoC Initiator Bridge per Target Bridge shows example connectivity for NoC target bridges where there is one local connection between one initiator bridge per target bridge. The NoC target bridge on the left connects to the RL0 and LR0 horizontal links. The NoC target bridge on the right connects to the RL1 and LR1 horizontal links. For simplicity, additional initiator bridge connections do not appear.

Figure 9. Example NoC Target Bridge Connectivity with Local Connection to One NoC Initiator Bridge per Target Bridge


Figure 10. Example NoC Target Bridge Connectivity with Local Connection to One NoC Initiator Bridge for Two Target Bridges shows example connectivity for NoC target bridges where adjacent target bridges have local connections to the same NoC initiator bridge. The NoC target bridge on the left connects to the RL1 and LR1 horizontal links. The NoC target bridge on the right connects to the RL0 and LR0 horizontal links. For simplicity, additional initiator bridge connections do not appear.

Figure 10. Example NoC Target Bridge Connectivity with Local Connection to One NoC Initiator Bridge for Two Target Bridges