| 摘要 |
Serialization of global operations within a multiprocessor system is achieved utilizing a single token, requiring a bus master to acquire the token for completion of one or more global operations to be initiated by that bus master. A combined token and operation request, in which a token request and an operation request are transmitted in a single bus transaction, is employed once for a global operation, to initiate the global operation for the first time. A token manager determines whether the token is available and released and, if available but not released, whether the token is checked out to the bus master originating the combined token and operation request. If the token is available and released or is available and was last checked out to the bus master originating the combined token and operation request, the token manager acknowledges to the token portion of the combined request; otherwise the token manager retries the token portion of the combined request. Snoopers respond to the operation portion of the combined request depending on whether they are busy. If the bus master to which the token was last checked out issues a combined token and operation request with release or a token request (only) with release followed by an operation request (only) with release, and a combined response acknowledging the combined token and operation request with release or the operation request (only) with release implies release of the token.
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