206 Hitachi
Table 8.2
Address Space and Cache Operation
Addresses
A31–A29
Partial Space
Cache Operation
000
Cache area
Cache is used when the CE bit of the CCR is 1.
001
Cache-through area
No cache is used.
010
Associative purge area
Cache line of the specified address is purged
(disabled).
011
Address array read/write area Cache address array is accessed directly.
110
Data array read/write area
Cache data array is accessed directly.
111
I/O area
No cache is used.
8.4
Cache Operation
8.4.1
Cache Reads
This section describes cache operation when the cache is enabled and data is read from the CPU.
One of the 64 entries is selected by the entry address part of the address output from the CPU on
the cache address bus. The tag addresses of ways 0 through 3 are compared to the tag address parts
of the addresses output from the CPU. A match to the tag address of a way is called a cache hit. In
proper use, the tag addresses of each way differ from each other, but and the tag address of only
one way will match. When none of the way tag addresses match, it is called a cache miss. Tag
addresses of entries with valid bits of 0 will not match in any case.
When a cache hit occurs, data is read from the data array of the way that was matched according to
the entry address, the byte address within the line, and the access data size. The data is then sent to
the CPU. The address output on the cache address bus is calculated in the CPU’s instruction
execution phase and the results of the read are written during the CPU’s write back stage. The
cache address bus and cache data bus both operate as pipelines in concert with the CPU’s pipeline
structure. From address comparison to data read requires 1 cycle; since the address and data
operate as a pipeline, consecutive reads can be performed at each cycle with no waits.
Содержание SH7095
Страница 1: ...SH7095 Hardware User Manual ...
Страница 16: ...Hitachi 5 1 2 Block Diagram Figure 1 1 is a block diagram of the SH7095 Figure 1 1 Block Diagram ...
Страница 23: ...12 Hitachi ...
Страница 63: ...52 Hitachi ...
Страница 77: ...66 Hitachi ...
Страница 105: ...94 Hitachi Figure 5 14 Pipeline Operation when Interrupts are Enabled by Changing the SR ...
Страница 127: ...116 Hitachi ...
Страница 152: ...Hitachi 141 Figure 7 8 Example of 32 Bit Data Width SRAM Connection ...
Страница 157: ...146 Hitachi Figure 7 13 Synchronous DRAM 32 bit Device Connection ...
Страница 161: ...150 Hitachi Figure 7 15 Basic Burst Read Timing Auto Precharge ...
Страница 167: ...156 Hitachi Figure 7 20 Burst Read Timing Bank Active Same Row Address ...
Страница 168: ...Hitachi 157 Figure 7 21 Burst Read Timing Bank Active Different Row Addresses ...
Страница 169: ...158 Hitachi Figure 7 22 Write Timing No Precharge ...
Страница 170: ...Hitachi 159 Figure 7 23 Write Timing Bank Active Same Row Address ...
Страница 178: ...Hitachi 167 a Phase Shifted 90 by PLL b Phase Shift Using PLL is 0 Figure 7 28 Phase Shift with the PLL ...
Страница 180: ...Hitachi 169 Figure 7 29 Example of a DRAM Connection 32 Bit Data Width ...
Страница 190: ...Hitachi 179 Figure 7 36 Example of Pseudo SRAM Connection 1 M pseudo SRAM ...
Страница 191: ...180 Hitachi Figure 7 37 Example of Pseudo SRAM Connection 4 M pseudo SRAM ...
Страница 209: ...198 Hitachi Figure 7 50 Master and Partial Share Master Connections ...
Страница 218: ...Hitachi 207 EX Instruction execution MA Memory Access WB Write back Figure 8 3 Reading during a Cache Hit ...
Страница 231: ...220 Hitachi ...
Страница 287: ...276 Hitachi ...
Страница 307: ...296 Hitachi Note For a CPU writing H AA55 to FRC Figure 11 2 FRC Access Operation Write ...
Страница 308: ...Hitachi 297 Note For an FRC reading from a CPU H AA55 Figure 11 3 FRC Access Operation Read ...
Страница 333: ...322 Hitachi ...
Страница 370: ...Hitachi 359 Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data ...
Страница 371: ...360 Hitachi Figure 13 12 Sample Flowchart for Receiving Multiprocessor Serial Data cont ...
Страница 395: ...384 Hitachi ...
Страница 402: ...Hitachi 391 Figure 15 6 PLL Synchronization Settling Timing ...
Страница 405: ...394 Hitachi Figure 15 7 Reset Input Timing Figure 15 8 Interrupt Signal Input Timing With PLL1 Off ...
Страница 408: ...Hitachi 397 Figure 15 13 Bus Release Timing Slave Mode With PLL1 Off ...
Страница 436: ...Hitachi 425 Figure 15 33 Synchronous DRAM Mode Register Write Cycle TRP 1 Cycle ...
Страница 437: ...426 Hitachi Figure 15 34 Synchronous DRAM Mode Register Write Cycle TRP 2 Cycles ...
Страница 439: ...428 Hitachi Figure 15 36 Synchronous DRAM Auto Refresh Cycle Shown From Precharge Cycle TRP 1 Cycle TRAS 2 Cycles ...
Страница 449: ...438 Hitachi Figure 15 46 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL On ...
Страница 454: ...Hitachi 443 Figure 15 51 DRAM CAS Before RAS Refresh Cycle TRP 1 Cycle TRAS 2 Cycles PLL Off ...
Страница 461: ...450 Hitachi Figure 15 58 Pseudo SRAM Auto Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Страница 462: ...Hitachi 451 Figure 15 59 Pseudo SRAM Self Refresh Cycle PLL On TRP 1 Cycle TRAS 2 Cycles ...
Страница 467: ...456 Hitachi Figure 15 64 Pseudo SRAM Auto Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Страница 468: ...Hitachi 457 Figure 15 65 Pseudo SRAM Self Refresh Cycle PLL Off TRP 1 Cycle TRAS 2 Cycles ...
Страница 471: ...460 Hitachi Figure 15 68 Interrupt Vector Fetch Cycle PLL On No Waits ...
Страница 472: ...Hitachi 461 Figure 15 69 Interrupt Vector Fetch Cycle PLL Off No Waits ...
Страница 473: ...462 Hitachi Figure 15 70 Interrupt Vector Fetch Cycle 1 External Wait Cycle ...
Страница 474: ...Hitachi 463 Figure 15 71 Address Monitor Cycle ...
Страница 490: ...Hitachi 479 B 2 Register Chart ...