|
The Dragon cache coherence protocol is the schema used in the Xerox Dragon multiprocessor workstation, developed by Xerox PARC. This protocol uses a write-back policy. == States == In this protocol, the following states can be assigned to each block: * Invalid: No data in cache block. * Clean: Clean, only copy. * Shared-Clean: Clean, might be shared. * Dirty: Modified, only copy. * Shared-Dirty: Modified, might be shared. This implies that there might be up-to-date other copies of the data (in Shared-Clean state) but that the memory copy is not up-to-date. These five states correspond to the five states of the MOESI protocol, although they are listed above in IESMO order. For any given pair of caches, the permitted states of a given cache line are as follows (the states abbreviated in the order above): 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dragon protocol」の詳細全文を読む スポンサード リンク
|