Renesas SH7781 - Manual (Page 221)

7. Memory Management Unit (MMU)
Rev.1.00 Jan. 10, 2008 Page 191 of 1658
REJ09B0261-0100
7.7.1 ITLB Address Array
The ITLB address array is allocated to addresses H'F200 0000 to H'F2FF FFFF in the P4 area. An
address array access requires a 32-bit address field specification (when reading or writing) and a
32-bit data field specification (when writing). Information for selecting the entry to be accessed is
specified in the address field, and VPN, V, and ASID to be written to the address array are
specified in the data field.
In the address field, bits [31:24] have the value H'F2 indicating the ITLB address array and the
entry is specified by bits [9:8]. As only longword access is used, 0 should be specified for address
field bits [1:0].
In the data field, bits [31:10] indicate VPN, bit [8] indicates V, and bits [7:0] indicate ASID.
The following two kinds of operation can be used on the ITLB address array:
1. ITLB address array read
VPN, V, and ASID are read into the data field from the ITLB entry corresponding to the entry
set in the address field.
2. ITLB address array write
VPN, V, and ASID specified in the data field are written to the ITLB entry corresponding to
the entry set in the address field.
Address field
31 23 0
1 1 1 1 0 0 0 0 1 0 E
Data field
31 10 9 0
V VPN
VPN:
V:
E:
*:
24
Virtual page number
Validity bit
Entry
Don't care
10 9 8 7 2 1
9 8 7
ASID
ASID:
:
Address space identifier
Reserved bits (write value should be 0,
and read value is undefined )
* * * * * * * * * * * * * * * * * * *
Figure 7.18 Memory-Mapped ITLB Address Array