SH7763 Datasheet, PDF (247/2026 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC Engine Family SH-4A Series

Section 6 Memory Management Unit (MMU)
6.7.4 PMB Function
This LSI supports the following PMB functions.
1. Only memory-mapped write can be used for writing to the PMB. The LDTLB instruction
cannot be used to write to the PMB.
2. Software must ensure that every accessed P1 or P2 address has a corresponding PMB entry
before the access occurs. When an access to an address in the P1 or P2 area which is not
recorded in the PMB is made, this LSI is reset by the TLB. In this case, the accessed address in
the P1 or P2 area which causes the TLB reset is stored in the TEA and code H′140 in the
EXPEVT.
3. This LSI does not guarantee the operation when multiple hit occurs in the PMB. Special care
should be taken when the PMB mapping information is recorded by software.
4. The PMB does not have an associative write function.
5. Since there is no PR field in the PMB, read/write protection cannot be preformed. The address
translation target of the PMB is the P1 or P2 address. In user mode access, an address error
exception occurs.
6. Both entries from the UTLB and PMB are mixed and recorded in the ITLB by means of the
hardware ITLB miss handling. However, these entries can be identified by checking whether
VPN[31:30] is 10 or not. When an entry from the PMB is recorded in the ITLB, H′00, 01, and
1 are recorded in the ASID, PR, and SH fields which do not exist in the PMB, respectively.
Rev. 1.00 Oct. 01, 2007 Page 181 of 1956
REJ09B0256-0100