Section 7 Caches
Rev. 1.00 Oct. 01, 2007 Page 197 of 1956
REJ09B0256-0100
7.3
Operand Cache Operation
7.3.1 Read
Operation
When the Operand Cache (OC) is enabled (OCE = 1 in CCR) and data is read from a cacheable
area, the cache operates as follows:
1. The tag, V bit, U bit, and LRU bits on each way are read from the cache line indexed by virtual
address bits [12:5].
2. The tag read from the each way is compared with bits [28:10] of the physical address resulting
from virtual address translation by the MMU:
•
If there is a way whose tag matches and its V bit is 1, see No. 3.
•
If there is no way whose tag matches and its V bit is 1 and the U bit of the way which is
selected to replace using the LRU bits is 0, see No. 4.
•
If there is no way whose tag matches and its V bit is 1 and the U bit of the way which is
selected to replace using the LRU bits is 1, see No. 5.
3. Cache hit
The data indexed by virtual address bits [4:0] is read from the data field of the cache line on
the hitted way in accordance with the access size. Then the LRU bits are updated to indicate
the hitted way is the latest one.
4. Cache miss (no write-back)
Data is read into the cache line on the way, which is selected to replace, from the physical
address space corresponding to the virtual address. Data reading is performed, using the
wraparound method, in order from the quad-word data(8 bytes) including the cache-missed
data. When the corresponding data arrives in the cache, the read data is returned to the CPU.
While the remaining data on the cache line is being read, the CPU can execute the next
processing. When reading of one line of data is completed, the tag corresponding to the
physical address is recorded in the cache, 1 is written to the V bit and 0 is written to the U bit
on the way. Then the LRU bit is updated to indicate the way is latest one.
Summary of Contents for SH7763
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Page 122: ...Section 2 Programming Model Rev 1 00 Oct 01 2007 Page 56 of 1956 REJ09B0256 0100 ...
Page 144: ...Section 3 Instruction Set Rev 1 00 Oct 01 2007 Page 78 of 1956 REJ09B0256 0100 ...
Page 170: ...Section 4 Pipelining Rev 1 00 Oct 01 2007 Page 104 of 1956 REJ09B0256 0100 ...
Page 282: ...Section 7 Caches Rev 1 00 Oct 01 2007 Page 216 of 1956 REJ09B0256 0100 ...
Page 378: ...Section 9 Interrupt Controller INTC Rev 1 00 Oct 01 2007 Page 312 of 1956 REJ09B0256 0100 ...
Page 514: ...Section 12 DDR SDRAM Interface DDRIF Rev 1 00 Oct 01 2007 Page 448 of 1956 REJ09B0256 0100 ...
Page 630: ...Section 13 PCI Controller PCIC Rev 1 00 Oct 01 2007 Page 564 of 1956 REJ09B0256 0100 ...
Page 710: ...Section 16 Clock Pulse Generator CPG Rev 1 00 Oct 01 2007 Page 644 of 1956 REJ09B0256 0100 ...
Page 732: ...Section 17 Watchdog Timer and Reset WDT Rev 1 00 Oct 01 2007 Page 666 of 1956 REJ09B0256 0100 ...
Page 752: ...Section 18 Power Down Mode Rev 1 00 Oct 01 2007 Page 686 of 1956 REJ09B0256 0100 ...
Page 772: ...Section 19 Timer Unit TMU Rev 1 00 Oct 01 2007 Page 706 of 1956 REJ09B0256 0100 ...
Page 824: ...Section 21 Compare Match Timer CMT Rev 1 00 Oct 01 2007 Page 758 of 1956 REJ09B0256 0100 ...
Page 1124: ...Section 26 I 2 C Bus Interface IIC Rev 1 00 Oct 01 2007 Page 1058 of 1956 REJ09B0256 0100 ...
Page 1350: ...Section 30 SIM Card Module SIM Rev 1 00 Oct 01 2007 Page 1284 of 1956 REJ09B0256 0100 ...
Page 1484: ...Section 33 Audio Codec Interface HAC Rev 1 00 Oct 01 2007 Page 1418 of 1956 REJ09B0256 0100 ...
Page 1560: ...Section 35 USB Host Controller USBH Rev 1 00 Oct 01 2007 Page 1494 of 1956 REJ09B0256 0100 ...
Page 1720: ...Section 37 LCD Controller LCDC Rev 1 00 Oct 01 2007 Page 1654 of 1956 REJ09B0256 0100 ...
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