Fujitsu Fujitsu SPARC64 V manual MMU TLB Tag Access Register, Kbyte page entry

Models: Fujitsu SPARC64 V

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FIGURE F-2Index number of set associative TLBs

RMD=00

8-Kbyte page entry

RMD=10

8-Kbyte page entry 4-Mbyte page entry

0

1024

way0

511

512

way1

0

511

512

way0

way1

1024

1535

1536

way0

way1

1023

2047

1023

2047

RMD=01

RMD=11

8-Kbyte page entry 4-Mbyte page entry

0

reserved

1023

1024

2047

reserved

0

511

512

1023

way0

way1

1024

1279

1280

1535

1536

1791

1792

2047

way0

reserved way1

reserved

I/D MMU TLB Tag Access Register

On an ASI store to the TLB Data Access or Data In Register, SPARC64 V verifies the consistency between the Tag Access Register and the data to be written. If their indexes are inconsistent, the TLB entry is not updated. However, SPARC64 V does not verify the consistency if TTE.V = 0 for the TTE to be written. This enables demapping of specified TLB entries through the TLB Data Access Register. Software can use this feature to validate faulty TLB entries.

On verifing the consistency, the bits position and length that is interpreted as index against the data in Tag Access Register varies on the page size and MCNTL.RMD. In 8- Kbyte page, bits[21:13] is conscidered as index and compared with the index field of TLB Data Access or Data In Register. In 4-Mbyte page, bits[30:22] when MCNTL.RMD=10, or bits[29:22] when MCNTL.RMD=11, is conscidered as index.

96 SPARC JPS1 Implementation Supplement: Fujitsu SPARC64 V • Release 1.0, 1 July 2002

Page 107
Image 107
Fujitsu Fujitsu SPARC64 V manual MMU TLB Tag Access Register, Kbyte page entry