Rev. 1.50, 10/04, page 159 of 448
Section 8 Caches
The SH-4A has an on-chip 32-Kbyte instruction cache (IC) for instructions and an on-chip 32-
Kbyte operand cache (OC) for data.
Note: For the size of instruction cache and operand cache, see the hardware manual of the target
product. This manual describes the 32-Kbyte case for each cache memory.
8.1 Features
The features of the cache are given in table 8.1.
The SH-4A supports two 32-byte store queues (SQs) to perform high-speed writes to external
memory. The features of the store queues are given in table 8.2.
Table 8.1
Cache Features
Item
Instruction Cache
Operand Cache
Capacity
32-Kbyte cache
32-Kbyte cache
Type
4-way set-associative, virtual
address index/physical address tag
4-way set-associative, virtual
address index/physical address tag
Line size
32 bytes
32 bytes
Entries
256 entries/way
256 entries/way
Write method
Copy-back/write-through
selectable
Replacement method
LRU (least-recently-used) algorithm LRU (least-recently-used) algorithm
Table 8.2
Store Queue Features
Item Store
Queues
Capacity 32
bytes
×
2
Addresses
H'E000 0000 to H'E3FF FFFF
Write Store
instruction (1-cycle write)
Write-back Prefetch
instruction (PREF instruction)
Access right
When MMU is disabled: Determined by SQMD bit in MMUCR
When MMU is enabled: Determined by PR for each page
Содержание SuperH SH-4A
Страница 2: ...Rev 1 50 10 04 page ii of xx ...
Страница 8: ...Rev 1 50 10 04 page viii of xx ...
Страница 116: ...Rev 1 50 10 04 page 96 of 448 ...
Страница 178: ...Rev 1 50 10 04 page 158 of 448 ...
Страница 206: ...Rev 1 50 10 04 page 186 of 448 ...
Страница 231: ...Rev 1 50 10 04 page 211 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 235: ...Rev 1 50 10 04 page 215 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 238: ...Rev 1 50 10 04 page 218 of 448 Possible Exceptions Slot illegal instruction exception ...
Страница 408: ...Rev 1 50 10 04 page 388 of 448 Possible Exceptions Inexact Not generated when FPSCR PR 1 ...
Страница 445: ...Rev 1 50 10 04 page 425 of 448 Possible Exceptions Invalid operation Overflow Underflow Inexact ...
Страница 446: ...Rev 1 50 10 04 page 426 of 448 ...
Страница 468: ...Rev 1 50 10 04 page 448 of 448 ...
Страница 471: ......
Страница 472: ...SH 4A Software Manual ...