r5s72060w200fpv Renesas Electronics Corporation., r5s72060w200fpv Datasheet - Page 205

• Manufacturer Part Number: r5s72060w200fpv
• Description: 32-bit Risc Microcomputer Superhtm Risc Engine Family / Sh7200 Series
• Manufacturer: Renesas Electronics Corporation.

(3)
With the 4-way set associative system, up to four instructions or data with the same entry address
can be registered in the cache. When an entry is registered, LRU shows which of the four ways it
is recorded in. There are six LRU bits, controlled by hardware. A least-recently-used (LRU)
algorithm is used to select the way that has been least recently accessed.
Six LRU bits indicate the way to be replaced in case of a cache miss. The relationship between
LRU and way replacement is shown in table 7.1 when the cache lock function (only for operand
cache) is not used (concerning the case where the cache lock function is used, see section 7.2.2,
Cache Control Register 2 (CCR2)). If a bit pattern other than those listed in table 7.1 is set in the
LRU bits by software, the cache will not function correctly. When modifying the LRU bits by
software, set one of the patterns listed in table 7.1.
The LRU bits are initialized to B'000000 by a power-on reset but not initialized by a manual reset
or in software standby mode.
Table 7.1
LRU (Bits 5 to 0)
000000, 000100, 010100, 100000, 110000, 110100
000001, 000011, 001011, 100001, 101001, 101011
000110, 000111, 001111, 010110, 011110, 011111
111000, 111001, 111011, 111100, 111110, 111111
LRU
LRU and Way Replacement (Cache Lock Function Not Used)
Rev. 2.00 Dec. 09, 2005 Page 181 of 1152
Way to be Replaced
3
2
1
0
REJ09B0191-0200
Section 7 Cache