r8a77850anbg Renesas Electronics Corporation., r8a77850anbg Datasheet - Page 239

• Manufacturer Part Number: r8a77850anbg
• Description: Renesas 32-bit Risc Microcomputer Superh? Risc Engine Family
• Manufacturer: Renesas Electronics Corporation.

7.10
7.10.1
When using an LDTLB instruction instead of software to a value to the MMUCR. URC, execute 1
or 2 below.
1. In 29-bit address mode, follow A. and B. below. In 32-bit address mode, follow A. through D.
2. If a TLB miss exception occurs, add 1 to MMUCR.URC before executing an LDTLB
below.
A. Place the TLB miss exception handling routine*
B. Use only one page of the PMB for instruction accesses*
C. In 32-bit address mode, obey 1 and 2 below when recording information in the UTLB in
D. Do not make an attempt to execute the FDIV or FSQRT instruction in the TLB miss
instruction.
memory so that all the instruction accesses*
should occur solely in the P1, P2 area, or the on-chip memory. Clear the RP bit in the
RAMCR register to 0 (initial value), when the TLB miss exception handling routine is
placed in the on-chip memory.
handling routine*
of the PMB.
the MMU-related exception*
a. When thea TLB miss exception occurs, and recording the information of a page with
b. When an initial page write exception occurs and the TLB entry in the UTLB of which
exception handling routine.
Usage Notes
Note on Using LDTLB Instruction
the access right in the UTLB, do not record the page, in which the exception has
occurred, in the UTLB using the following two operations.
the dirty bit is 1 is replaced, before the write instruction for the page corresponding to
this replaced TLB entry is completed, register the TLB entry of which the dirty bit is 1.
⎯ Specifies the protection key data that causes a protection violation exception upon
⎯ Specifies the protection key data that does not cause a protection violation
re-execution of the instruction that has caused the TLB miss exception and records
the page, in which the TLB miss exception has occurred, in the UTLB.
exception in the protection violation exception handling routine to record the page
in the UTLB and re-executes the instruction that has caused the protection violation
exception.
1
. In 32-bit address mode, do not place them in the last 64 bytes of a page
2
handling routine.
3
in the TLB miss exception handling routine
1
only in the P1, P2 area ,or the on-chip
Rev.1.00 Jan. 10, 2008 Page 209 of 1658
3
in the TLB miss exception
7. Memory Management Unit (MMU)
REJ09B0261-0100