HD6417320 RENESAS [Renesas Technology Corp], HD6417320 Datasheet - Page 243

• Manufacturer Part Number: HD6417320
• Description: Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7700 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

3. There is the possibility of simultaneous TLB hits in more than one way. These hits may occur
The object compared varies depending on the page management information (SZ, SH) in the TLB
entry. It also varies depending on whether the system supports multiple virtual memory or single
virtual memory.
The page-size information determines whether VPN (11 to 10) is compared. VPN (11 to 10) is
compared for 1-kbyte pages (SZ = 0) but not for 4-kbyte pages (SZ = 1).
The sharing information (SH) determines whether the PTEH.ASID and the ASID in the TLB entry
are compared. ASIDs are compared when there is no sharing between processes (SH = 0) but not
when there is sharing (SH = 1).
When single virtual memory is supported (MMUCR.SV = 1) and privileged mode is engaged
(SR.MD = 1), all process resources can be accessed. This means that ASIDs are not compared
when single virtual memory is supported and privileged mode is engaged. The objects of address
comparison are shown in figure 4.10.
depending on the contents of ASID in PTEH when a page to which SH is set 1 is registered in
the TLB in index mode (MMUCR.IX = 1). Therefore a page to which SH is set 1 must not be
registered in index mode. When memory is shared by several processings, different pages must
be registered in each ASID.
MMUCR.SV = 1)?
(SR.MD = 1 and
Bits compared:
VPN 31 to 17
VPN 11 to 10
SH = 1 or
SZ = 0?
Yes
Yes (1-kbyte)
Figure 4.10 Objects of Address Comparison
Bits compared:
VPN 31 to 17
No (4-kbyte)
No
Bits compared:
VPN 31 to 17
VPN 11 to 10
ASID 7 to 0
Section 4 Memory Management Unit (MMU)
SZ = 0?
Rev. 3.00 Jan. 18, 2008 Page 181 of 1458
Yes (1-kbyte)
Bits compared:
VPN 31 to 17
ASID 7 to 0
No (4-kbyte)
REJ09B0033-0300