HD6417750 Datasheet, PDF (143/1039 Pages) Renesas Technology Corp – SuperH RISC engine

In the address field, bits [31:24] have the value H'F6 indicating the UTLB address array, and the
entry is selected by bits [13:8]. The address array bit [7] association bit (A bit) specifies whether
or not address comparison is performed when writing to the UTLB address array.
In the data field, VPN is indicated by bits [31:10], D by bit [9], V by bit [8], and ASID by bits
[7:0].
The following three kinds of operation can be used on the UTLB address array:
1. UTLB address array read
VPN, D, V, and ASID are read into the data field from the UTLB entry corresponding to the
entry set in the address field. In a read, associative operation is not performed regardless of
whether the association bit specified in the address field is 1 or 0.
2. UTLB address array write (non-associative)
VPN, D, V, and ASID specified in the data field are written to the UTLB entry corresponding
to the entry set in the address field. The A bit in the address field should be cleared to 0.
3. UTLB address array write (associative)
When a write is performed with the A bit in the address field set to 1, comparison of all the
UTLB entries is carried out using the VPN specified in the data field and PTEH.ASID. The
usual address comparison rules are followed, but if a UTLB miss occurs, the result is no
operation, and an exception is not generated. If the comparison identifies a UTLB entry
corresponding to the VPN specified in the data field, D and V specified in the data field are
written to that entry. If there is more than one matching entry, a data TLB multiple hit
exception results. This associative operation is simultaneously carried out on the ITLB, and if
a matching entry is found in the ITLB, V is written to that entry. Even if the UTLB
comparison results in no operation, a write to the ITLB side only is performed as long as there
is an ITLB match. If there is a match in both the UTLB and ITLB, the UTLB information is
also written to the ITLB.
31
24 23
Address field _{1 1 1 1 0 1 1 0}
14 13
87
E
A
210
31 30 29 28
Data field
VPN
10 9 8 7
DV
0
ASID
VPN: Virtual page number
V: Validity bit
E: Entry
D: Dirty bit
ASID: Address space identifier
A: Association bit
: Reserved bits (0 write value, undefined
read value)
Figure 3.16 Memory-Mapped UTLB Address Array
Rev. 6.0, 07/02, page 91 of 986