Dstream Tb Address Space Number Registers 0 And 1 - Dtb_Asn0,1; Memory Management Status Register - Mm_Stat; Dstream Translation Buffer Address Space Number Registers 0 And 1 . . . . . . . . . . . . . . . . 5-31 Memory Management Status Register; Memory Management Status Register Fields Description - Compaq 21264 Hardware Reference Manual

Mbox IPRs
5.3.7 Dstream TB Address Space Number Registers 0 and 1 – DTB_ASN0,1
The Dstream translation buffer address space number registers (DTB_ASN0 and
DTB_ASN1) are write-only registers that should be written with the address space
number (ASN) of the current process. Figure 5–30 shows the Dstream translation buffer
address space number registers 0 and 1.
Figure 5–30 Dstream Translation Buffer Address Space Number Registers 0 and 1
63 56 55
ASN[7:0]
5.3.8 Memory Management Status Register – MM_STAT
The memory management status register (MM_STAT) is a read-only register.
When a Dstream TB miss or fault occurs, information about the error is latched in
MM_STAT. MM_STAT is not updated when a LD_VPTE gets a DTB miss instruction.
Figure 5–31 shows the memory management status register.
Figure 5–31 Memory Management Status Register
63
DC_TAG_PERR
OPCODE[5:0]
FOW
FOR
ACV
WR
Table 5–18 describes the memory management status register fields.
Table 5–18 Memory Management Status Register Fields Description
Name
Reserved
DC_TAG_PERR
OPCODE[5:0]
FOW
Internal Processor Registers
5–28
Extent Type Description
[63:11] — —
[10] RO This bit is set when a Dcache tag parity error occurred during the
initial tag probe of a load or store instruction. The error created a
synchronous fault to the D_FAULT PALcode entry point and is
correctable. The virtual address associated with the error is avail-
able in the VA register.
[9:4] RO Opcode of the instruction that caused the error.
HW_LD is displayed as 3 and HW_ST is displayed as 7.
[3] RO This bit is set when a fault-on-write error occurs during a write
transaction and PTE[FOW] was set.
Alpha 21264/EV67 Hardware Reference Manual
0
LK99-0038A
11 10 9 4 3 2 1 0
LK99-0039A