Section 3 Memory Management Unit (MMU)
Rev. 5.00 May 29, 2006 page 61 of 698
REJ09B0146-0500
31
9
VPN
Virtual address (1-kbyte page)
Virtual address (4-kbyte page)
TLB entry
Offset
VPN
VPN (31–17)
VPN (11, 10)
ASID
V
PPN
C
D
Offset
0
10
31
11
0
(15)
(2)
PR
(2)
(22)
(8)
(1)
(1) (1)
SH
(1)
SZ
(1)
12
VPN: Virtual page number. Top 22 bits of virtual address for a 1-kbyte page, or top 20 bits of
virtual address for a 4-kbyte page. Since VPN bits 16–12 are used as the index number,
they are not stored in the TLB entry.
ASID: Address space identifier. Indicates the process that can access a virtual page. In single
virtual memory mode and user mode, or in multiple virtual memory mode, if the SH bit is
0, the address is compared with the ASID in PTEH when address comparison is
performed.
SH: Share status bit
0 = Page not shared between processes
1 = Page shared between processes
SZ:
Page-size
bit
0 = 1-kbyte page
1 = 4-kbyte page
V: Valid bit. Indicates whether entry is valid.
0 = Invalid
1
=
Valid
Cleared to 0 by a power-on reset. Not affected by a manual reset.
PPN: Physical page number. Top 22 bits of physical address. PPN bits 11–10 are not used in
case of a 4-kbyte page. Attention must be paid to the synonym problem in case of a 1-
kbyte page (see section 3.4.4 Avoiding Synonym Problems).
PR: Set the most significant bit to 0.
Protection key field. 2-bit field encoded to define the access rights to the page.
00: Reading only is possible in privileged mode.
01: Reading/writing is possible in privileged mode.
10: Reading only is possible in privileged/user mode.
11: Reading/writing is possible in privileged/user mode.
C: Cacheable bit. Indicates whether the page is cacheable.
0:
Non-cacheable
1:
Cacheable
D: Dirty bit. Indicates whether the page has been written to.
0 = Not written to
1 = Written to
Legend
Figure 3.4 Virtual Address and TLB Structure
Summary of Contents for SH7706 Series
Page 8: ...Rev 5 00 May 29 2006 page viii of xlviii ...
Page 160: ...Section 5 Cache Rev 5 00 May 29 2006 page 112 of 698 REJ09B0146 0500 ...
Page 370: ...Section 11 Watchdog Timer WDT Rev 5 00 May 29 2006 page 322 of 698 REJ09B0146 0500 ...
Page 554: ...Section 17 Pin Function Controller PFC Rev 5 00 May 29 2006 page 506 of 698 REJ09B0146 0500 ...
Page 576: ...Section 18 I O Ports Rev 5 00 May 29 2006 page 528 of 698 REJ09B0146 0500 ...
Page 746: ...Index Rev 5 00 May 29 2006 page 698 of 698 REJ09B0146 0500 ...
Page 749: ...SH7706 Group Hardware Manual ...