Renesas SuperH SH-4A - Page 101

Rev. 1.50, 10/04, page 81 of 448
Instruction TLB Protection Violation Exception:
• Source: The access does not accord with the ITLB protection information (PR bits) shown
below.
PR Privileged Mode User Mode
0 Access possible Access not possible
1 Access possible Access possible
• Transition address: VBR + H'00000100
• Transition operations:
The virtual address (32 bits) at which this exception occurred is set in TEA, and the
corresponding virtual page number (22 bits) is set in PTEH [31:10]. ASID in PTEH indicates
the ASID when this exception occurred.
The PC and SR contents for the instruction at which this exception occurred are saved in SPC
and SSR. The R15 contents at this time are saved in SGR.
Exception code H'0A0 is set in EXPEVT. The BL, MD, and RB bits are set to 1 in SR, and a
branch is made to PC = VBR + H'0100.
ITLB_protection_violation_exception()
{
TEA = EXCEPTION_ADDRESS;
PTEH.VPN = PAGE_NUMBER;
SPC = PC;
SSR = SR;
SGR = R15;
EXPEVT = H'0000 00A0;
SR.MD = 1;
SR.RB = 1;
SR.BL = 1;
PC = VBR + H'0000 0100;
}