Intel 80312 I/O Companion Chip - ECEE

Intel ® 80312 I/O Companion ChipPCI-to-PCI Bridge UnitTable 4-18 summarizes the transaction ordering tables in relation to token assignment of thepriority mechanism. This table is read as follow:1. As the transaction reaches the respective queue head, the question in column two is asked.2. Based on the answer in column three, either a token is assigned or no token is assignedsignifying that transaction ordering must first be satisfied. Note that when the answer isYes/No in column three, the Action in column four is for either a Yes or a No.Table 4-18.Bridge Transaction Ordering and Priority MechanismTransaction atHead of QueueQuestion Answer ActionPosted MemoryWrite in PMWDDelayed ReadRequest inTRQ0:2Delayed WriteRequest in TRQ3Is there a DRR in a TRQ0:2 queue with an earlier time stamp? Yes/No Assign TokenIs there a DRC in DRC0:2 with an earlier time stamp? Yes/No Assign TokenIs there a DWR in TRQ3 with an earlier time stamp? Yes/No Assign TokenIs there a DWC in DWC queue with an earlier time stamp? Yes/No Assign TokenIsthereaPMWinthePMWDqueuewithanearliertimestamp? YesDo Not AssignTokenAllow previousTransaction toCompleteIs there a PMW in the PMWD queue with an earlier time stamp? No Assign TokenIs there a DRR in a TRQ0:2 queue with an earlier time stamp? Yes/No Assign TokenIs there a DRC in DRC0:2 with an earlier time stamp? Yes/No Assign TokenIs there a DWR in TRQ3 with an earlier time stamp? Yes/No Assign TokenIs there a DWC in DWC queue with an earlier time stamp? Yes/No Assign TokenIsthereaPMWinthePMWDqueuewithanearliertimestamp?YesDo Not AssignTokenAllow previousTransaction toCompleteIs there a PMW in the PMWD queue with an earlier time stamp? No Assign TokenIs there a DRR in a TRQ0:2 queue with an earlier time stamp? Yes/No Assign TokenIs there a DRC in DRC0:2 with an earlier time stamp? Yes/No Assign TokenIs there a DWC in DWC queue with an earlier time stamp? Yes/No Assign TokenIsthereaPMWinthePMWDqueuewithanearliertimestamp?YesDo Not AssignTokenAllow previousTransaction toCompleteDelayed ReadCompletion inDRC0:2Is there a PMW in the PMWD queue with an earlier time stamp? No Assign TokenDelayed WriteCompletion inDWCIs there a DRR in a TRQ0:2 queue with an earlier time stamp? Yes/No Assign TokenIs there a DRC in DRC0:2 with an earlier time stamp? Yes/No Assign TokenIs there a DWR in TRQ3 with an earlier time stamp? Yes/No Assign TokenIs there a DWC in DWC queue with an earlier time stamp? Yes/No Assign TokenIs there a PMW in the PMWD queue with an earlier time stamp? Yes/No Assign TokenIs there a DRR in a TRQ0:2 queue with an earlier time stamp? Yes/No Assign TokenIs there a DRC in DRC0:2 with an earlier time stamp? Yes/No Assign TokenIs there a DWR in TRQ3 with an earlier time stamp? Yes/No Assign Token4-54 Developer’s Manual