Accelerated Graphics Port Interface Specification

AGP3.0 Interface Specification
Rev. 1.0
7
5.3.1 AGP Aperture Page Size....................................................................................................117
5.3.2 AGP Graphics Aperture Requirements..............................................................................117
5.3.3 GART Overview .................................................................................................................118
5.3.4 GART Requirements..........................................................................................................118
5.3.5 Requirements for Modifying GART Entries........................................................................120
5.4 Coherency Requirements.........................................................................................................121
5.4.1 Coherency of Host Processor Accesses ..........................................................................122
5.5 System Software Initialization...................................................................................................122
5.6 AGP Registers..........................................................................................................................123
5.6.1 Register Set Support Requirements..................................................................................124
5.7 Register Table Format..............................................................................................................125
5.8 Required Master and Target Registers ....................................................................................126
5.8.1 PCISTS: PCI STATUS REGISTER ...................................................................................126
5.8.2 CAPPTR: CAPABILITIES POINTER..................................................................................126
5.8.3 NCAPID: AGP IDENTIFIER REGISTER............................................................................127
5.8.4 AGPSTAT: AGP STATUS REGISTER ..............................................................................128
5.8.5 AGPCMD: AGP COMMAND REGISTER...........................................................................130
5.8.6 NISTAT: AGP ISOCHRONOUS STATUS REGISTER......................................................133
5.8.7 NICMD: AGP ISOCHRONOUS COMMAND REGISTER ..................................................135
5.9 Required Target Registers .......................................................................................................137
5.9.1 APBASELO: AGP APERTURE BASE LOW ADDRESS REGISTER ..............................137
5.9.2 APBASEHI: AGP APERTURE BASE ADDRESS HIGH REGISTER ................................138
5.9.3 AGPCTRL: AGP CONTROL REGISTER..........................................................................139
5.9.4 APSIZE: AGP APERTURE SIZE........................................................................................140
5.9.5 NEPG: AGP ENABLED APERTURE PAGE SIZE .............................................................141
5.9.6 GARTLO: AGP GART POINTER.......................................................................................142
5.9.7 GARTHI: AGP GART POINTER HIGH...............................................................................142
6 APPENDIX C: GLOSSARY OF TERMS ...............................................................143