Section 8 Cache
Rev. 2.00 Mar 09, 2006 page 365 of 906
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Address A
MA
EX
EX
MA
Cache tag comparison
Cache tag comparison
Data array write
Address A
Address A
+12
Address A
+8
Address A
+4
Address A
Address A
+12
Address A
+8
Address A
+4
Address B
Address A
CPU
pipeline
stage
I
φ
Cache
address
bus
Cache
data bus
Internal
address
bus
EX: Instruction execution
MA: Memory access
Internal
data bus
Figure 8.7 Write Access in Case of a Cache Miss (Write-Back)
When the update bit of an entry to be replaced in write-back mode is 1, write-back to external
memory is necessary. To improve performance, the entry to be replaced is first transferred to the
write-back buffer, and fetching of the new entry into the cache is given priority over the write-
back. When the new entry has been fetched into the cache, the write-back buffer contents are
written back to external memory. The cache can be accessed during this write-back.
The write-back buffer can hold one cache line (16 bytes) of data and its address. The configuration
of the write-back buffer is shown in figure 8.8.
A (31–4):
Address for write-back to external memory
Longwords 0–3: One cache line of data for write-back to external memory
A (31–4)
Longword 0
Longword 1
Longword 2
Longword 3
Figure 8.8 Write-Back Buffer Configuration
Summary of Contents for SH7616
Page 10: ...Rev 2 00 Mar 09 2006 page x of xxvi ...
Page 132: ...Section 2 CPU Rev 2 00 Mar 09 2006 page 106 of 906 REJ09B0292 0200 ...
Page 568: ...Section 12 16 Bit Free Running Timer FRT Rev 2 00 Mar 09 2006 page 542 of 906 REJ09B0292 0200 ...
Page 582: ...Section 13 Watchdog Timer WDT Rev 2 00 Mar 09 2006 page 556 of 906 REJ09B0292 0200 ...
Page 706: ...Section 16 Serial I O SIO Rev 2 00 Mar 09 2006 page 680 of 906 REJ09B0292 0200 ...
Page 820: ...Section 19 Pin Function Controller PFC Rev 2 00 Mar 09 2006 page 794 of 906 REJ09B0292 0200 ...
Page 932: ...Appendix D Package Dimensions Rev 2 00 Mar 09 2006 page 906 of 906 REJ09B0292 0200 ...
Page 935: ...SH7616 Hardware Manual ...