Each master of the interconnect is configured with one of three possible cyclic dependency avoidance schemes
(CDAS). The same CDAS scheme is configured for both read and write transactions, but they operate
independently.
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Related Information
Interconnect Master Properties
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Contains descriptions of the CDAS implementation for the masters.
Single Slave
Single slave (SS) ensures the following conditions at a slave interface of a switch:
• All outstanding read transactions are to a single end destination.
• All outstanding write transactions are to a single end destination.
If a master issues another transaction to a different destination than the current destination for that
transaction type (read or write), the network stalls the transactions until all the outstanding transactions of
that type have completed.
Single Slave Per ID
Single slave per ID (SSPID) ensures the following conditions at a slave interface of a switch:
• All outstanding read transactions with the same ID go the same destination.
• All outstanding write transactions with the same ID go the same destination.
When a master issues a transaction, the following situations can occur:
• If the transaction has an ID that does not match any outstanding transactions, it passes the CDAS.
• If the transaction has an ID that matches the ID of an outstanding transaction, and the destinations also
match, it passes the CDAS.
• If the transaction has an ID that matches the ID of an outstanding transaction, and the destinations do
not match, the transaction fails the CDAS check and stalls.
Single Active Slave
Single active slave (SAS) is the same as the SSPID scheme, with an added check for write transactions. SAS
ensures that a master cannot issue a new write address until all of the data from the previous write transaction
has been sent.
Interconnect Master Properties
The interconnect connects to various slave interfaces through the L3 main switch and L3 slave peripheral
switch.
Interconnect
Altera Corporation
cv_54004
Single Slave
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2013.12.30