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Cache
6-24
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The following tables present the same information as
, organized by the current state of the cache
the current state is invalid.
Table 6-7. Data Cache Line State Transitions (Current State Invalid)
Access
Response
Read miss
(C,W)I1 Read line from memory and update cache;
supply data to processor;
go to valid state.
Read hit
(C,W)I2 Not possible
Write miss (copyback)
CI3
Read line from memory and update cache;
write data to cache;
go to modified state.
Write miss (write-through)
WI3
Write data to memory;
stay in invalid state.
Write hit (copyback)
CI4
Not possible
Write hit (write-through)
WI4
Not possible
Cache invalidate
(C,W)I5 No action;
stay in invalid state.
Cache push
(C,W)I6 No action;
stay in invalid state.
Cache push
(C,W)I7 No action;
stay in invalid state.
Table 6-8. Data Cache Line State Transitions (Current State Valid)
Access
Response
Read miss
(C,W)V1
Read new line from memory and update cache;
supply data to processor; stay in valid state.
Read hit
(C,W)V2
Supply data to processor;
stay in valid state.
Write miss (copyback)
CV3
Read new line from memory and update cache;
write data to cache;
go to modified state.
Write miss (write-through)
WV3
Write data to memory;
stay in valid state.
Write hit (copyback)
CV4
Write data to cache;
go to modified state.
Write hit (write-through)
WV4
Write data to memory and to cache;
stay in valid state.
Cache invalidate
(C,W)V5
No action;
go to invalid state.
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...