General Exceptions - Hitachi SH7751 Hardware Manual

5.6.2

General Exceptions

(1) Data TLB Miss Exception


Source: Address mismatch in UTLB address comparison


Transition address: VBR + H'0000 0400


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'040 (for a read access) or H'060 (for a write access) 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'0400.
To speed up TLB miss processing, the offset is separate from that of other exceptions.
Data_TLB_miss_exception()
{
TEA = EXCEPTION_ADDRESS;
PTEH.VPN = PAGE_NUMBER;
SPC = PC;
SSR = SR;
SGR = R15;
EXPEVT = read_access ? H'00000040 : H'00000060;
SR.MD = 1;
SR.RB = 1;
SR.BL = 1;
PC = VBR + H'00000400;
}
Rev. 3.0, 04/02, page 134 of 1064