![](http://datasheet.mmic.net.cn/120000/SH7709_datasheet_3575232/SH7709_85.png)
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Hardware Operations: In a TLB protection violation exception, the SH7709 hardware executes a
set of prescribed operations, as follows:
1. The VPN field of the virtual address causing the exception is written to the PTEH register.
2. The virtual address causing the exception is written to the TEA register.
3. Either exception code H'0A0 for a load access, or H'0C0 for a store access, is written to the
EXPEVT register.
4. The PC value indicating the address of the instruction in which the exception occurred is
written into SPC (if the exception occurred in a delay slot, the PC value indicating the address
of the related delayed branch instruction is written into SPC).
5. The contents of SR at the time of the exception are written to SSR.
6. The MD bit in SR is set to 1 to place the SH7709 in privileged mode.
7. The BL bit in SR is set to 1 to mask any further exception requests.
8. The register bank (RB) bit in SR is set to 1.
9. The way that generated the exception is set in the RC field in MMUCR.
10. Execution branches to the address obtained by adding the value of the VBR contents and
H'00000100 to invoke the TLB protection violation exception handler.
Software (TLB Protection Violation Handler) Operations: The software resolves the TLB
protection violation and issues the RTE (return from exception handler) instruction to terminate
the handler and return to the instruction stream.
3.5.3
TLB Invalid Exception
A TLB invalid exception results when the virtual address is compared to a selected TLB entry
address array and a match is found but the entry is not valid (the V bit is 0). TLB invalid exception
handling includes both hardware and software operations.
Hardware Operations: In a TLB invalid exception, the SH7709 hardware executes a set of
prescribed operations, as follows:
1. The VPN number of the virtual address causing the exception is written to the PTEH register.
2. The virtual address causing the exception is written to the TEA register.
3. The way number causing the exception is written to RC in MMUCR.
4. Either exception code H'040 for a load access, or H'060 for a store access, is written to the
EXPEVT register.
5. The PC value indicating the address of the instruction in which the exception occurred is
written to the SPC. If the exception occurred in a delay slot, the PC value indicating the
address of the delayed branch instruction is written to the SPC.
6. The contents of SR at the time of the exception are written into SSR.
7. The mode (MD) bit in SR is set to 1 to place the SH7709 in privileged mode.
8. The block (BL) bit in SR is set to 1 to mask any further exception requests.