Write Ordering - 1.0 English

Versal Adaptive SoC Programmable Network on Chip and Integrated Memory Controller 1.0 LogiCORE IP Product Guide (PG313)

Document ID
PG313
Release Date
2024-05-30
Version
1.0 English

The NoC generally uses the Single Slave per ID (SSID) rule for write requests, but the HBM_NMU implementation allows three different types of write ordering to choose from:

Strict
This type of write request must follow the SSID rule. It ensures the NMU receives the write response from one NSU before issuing a new write request to another NSU, when both the requests have the same AXI ID and a different destID.
Relaxed
This write ordering rule requires the write requests with the same AXI ID to have their responses returned in the same order as the requests as well; however, the NMU will not block a new write request. It will be sent out immediately.
Doorbell
This write ordering rule flushes all previous relaxed write order requests from the same AXI ID. It follows the SSID rule for other types of previous write order requests (strict/doorbell), in which case it ensures the NMU receives the write response for one NSU before issuing a new write request to another NSU, when both the requests have the same AXI ID and different destID.
Note: The other versions of the NMUs allow only Strict Order.