Table of Contents
Advertisement
(7) Instruction Address Error
• Sources:
Instruction fetch from other than a word boundary (2n +1)
Instruction fetch from area H'8000 0000–H'FFFF FFFF in user mode
• Transition address: VBR + H'0000 0100
• 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 the
SPC and SSR.
Exception code H'0E0 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. For details, see section 3, Memory Management Unit
(MMU).
Instruction_address_error()
{
TEA = EXCEPTION_ADDRESS;
PTEN.VPN = PAGE_NUMBER;
SPC = PC;
SSR = SR;
EXPEVT = H'000000E0;
SR.MD = 1;
SR.RB = 1;
SR.BL = 1;
PC = VBR + H'00000100;
}
Rev. 2.0, 03/99, page 103 of 396
Advertisement
Table of Contents
