Visible to Intel only — GUID: vmh1734368816670
Ixiasoft
Visible to Intel only — GUID: vmh1734368816670
Ixiasoft
5.10.6.2. Enabling Out-Of-Order Transactions
When using AXI interfaces, Platform Designer interconnect supports out-of-order transactions by utilizing the AXI ID. IDs Returning Data Values Out of Order illustrates how different IDs can return data values out of order. Transaction 1, 2 and 3 do not return in-order, with B returning after C and D.
Out-of-order transaction support enables the reordering ability of one subordinate from multiple managers (Mx1 support). For connections from manager to subordinate that involve width or burst adapters that can split a manager's sent command into smaller pieces, Platform Designer places re-ordering buffers (ROB) to reassemble the split responses before returning them to manager. The ROB is an automatically added module based on your configuration, similar to how Platform Designer automatically adds adapters in interconnect.
You must first enable out-of-order transaction support in Platform Designer before use. To enable out-of order transactions for AXI in Platform Designer, follow these steps:
- In Platform Designer, open a system that contains a manager to subordinate connection.
- To open the Domains tab, click View > Domains.
- In the Domains tab, click the manager to subordinate connection under Memory Mapped Domains. The Interconnect Parameters for the connection appear.
- For the Enable Out of Order support parameter, select True.
Figure 243. Enabling Out of Order Support Parameter
To modify the number of reads that a subordinate can reorder, follow these steps:
- In the Platform Designer System Contents tab, right-click the AXI subordinate IP, and then click Edit Component Instantiation.
- In the Signals & Interfaces tab, select the AXI subordinate.
- Specify a value for the Read data reordering depth parameter. By default, the value is 1.
- Click the Finish button.
Figure 244. Specifying Read Data Reordering Depth Parameter