Header files: incl/MemSys/req.h
The fundamental unit of information exchange among the RSIM memory
system simulator modules is referred to in this manual as a memory
system message
. This data structure
conveys essential information about the access being simulated,
just as the instance structure acts as the basic
unit of information exchange among the processor pipeline stages.
The memory system message specifies an action that must be performed on a certain portion of the memory hierarchy, as described below. The five most important fields of the message data structure are the tag field, the s.type field, the req_type field, the s.reply field, and the s.nack_st field. The tag field specifies the cache line to which the action in question applies. This field is used with the same meaning in all varieties of messages. The following sections describe how each of the other fields is used to distinguish the types of messages in the memory system simulator.