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Rev. 5.00, 09/03, page 96 of 760
• TLB invalid exception
Conditions: Comparison of TLB addresses shows address match but the TLB entry valid
bit (V) is 0.
Operations: The virtual address (32 bits) that caused the exception is set in TEA and the
corresponding virtual page number (22 bits) is set in PTEH (31–10). The ASID of PTEH
indicates the ASID at the time the exception occurred. The way that generated the
exception is set in the RC bits in MMUCR.
PC and SR of the instruction that generated the exception are saved to SPC and SSR,
respectively. If the exception occurred during a read, H'040 is set in EXPEVT; if the exception
occurred during a write, H'060 is set in EXPEVT. The BL, MD, and RB bits in SR are set to 1
and a branch occurs to PC = VBR + H'0100.
• Initial page write exception
Conditions: A hit occurred to the TLB for a store access, but the TLB entry data bit (D) is
0.
This occurs for initial writes to the page registered by the load.
Operations: The virtual address (32 bits) that caused the exception is set in TEA and the
corresponding virtual page number (22 bits) is set in PTEH (31–10). The ASID of PTEH
indicates the ASID at the time the exception occurred. The way that generated the
exception is set in the RC bit in MMUCR.
PC and SR of the instruction that generated the exception are saved to SPC and SSR,
respectively. H'080 is set in EXPEVT. The BL, MD, and RB bits in SR are set to 1 and a
branch occurs to PC = VBR + H'0100.
• TLB protection exception
Conditions: When a hit access violates the TLB protection information (PR bits) shown
below:
PR Privileged mode User mode
00 Only read enabled No access
01 Read/write enabled No access
10 Only read enabled Only read enabled
11 Read/write enabled Read/write enabled
Operations: The virtual address (32 bits) that caused the exception is set in TEA and the
corresponding virtual page number (22 bits) is set in PTEH (31–10). The ASID of PTEH
indicates the ASID at the time the exception occurred. The way that generated the
exception is set in the RC bits in MMUCR.
PC and SR of the instruction that generated the exception are saved to SPC and SSR,
respectively. If the exception occurred during a read, H'0A0 is set in EXPEVT; if the exception
occurred during a write, H'0C0 is set in EXPEVT. The BL, MD, and RB bits in SR are set to 1
and a branch occurs to PC = VBR + H'0100.