Mips Technologies R4000 - Page 24

Table of Contents
xxiv MIPS R4000 Microprocessor User's Manual
12
System Interface
Terminology..............................................................................................................294
System Interface Description..................................................................................294
Interface Buses......................................................................................................295
Address and Data Cycles ...............................................................................296
Issue Cycles ......................................................................................................296
Handshake Signals..............................................................................................298
System Interface Protocols......................................................................................299
Master and Slave States.......................................................................................299
Moving from Master to Slave State...................................................................300
External Arbitration.............................................................................................300
Uncompelled Change to Slave State .................................................................301
Processor and External Requests ...........................................................................302
Rules for Processor Requests..............................................................................303
Processor Requests............................................................................................... 304
Processor Read Request..................................................................................306
Processor Write Request................................................................................. 307
Processor Invalidate Request.........................................................................308
Processor Update Request..............................................................................310
Clusters..............................................................................................................311
External Requests.................................................................................................313
External Read Request....................................................................................316
External Write Request ...................................................................................316
External Invalidate Request ........................................................................... 316
External Update Request................................................................................ 316
External Snoop Request.................................................................................. 317
External Intervention Request .......................................................................317
Read Response .................................................................................................317
Handling Requests...................................................................................................318
Load Miss..............................................................................................................318
Secondary-Cache Mode..................................................................................320
No-Secondary-Cache Mode ...........................................................................320
Store Miss..............................................................................................................321
Secondary-Cache Mode..................................................................................323
No-Secondary-Cache Mode ...........................................................................325
Store Hit................................................................................................................. 326
Secondary-Cache Mode..................................................................................326