Compaq 21264 Hardware Reference Manual page 318

Restriction 40: Scrubbing a Single-Bit Error
hw_mtpr r31, EV6__DTB_IA
lda
bis
bis
hw_mtpr r31, <EV6__MM_STAT ! ^x80>
srl
sll
bis
hw_mtpr r4, EV6__DTB_TAG0
hw_mtpr r4, EV6__DTB_TAG1
hw_mtpr r6, EV6__DTB_PTE0
hw_mtpr r6, EV6__DTB_PTE1
mb
bis
bis
bis
ldq
ldq
ldq
ldq
ldq
ldq
ldq
mb
ldq_l
stq_c
mb
and
beq
br
sys__crd_scrub_done:
bsr
bis
hw_mtpr r31, EV6__DTB_IA
bis
bis
bis
hw_mtpr r31, <EV6__MM_STAT ! ^x80>
bis
sll
hw_mtpr r7, EV6__HW_INT_CLR
lda
hw_mtpr r7, EV6__DC_STAT
bis
bis
hw_mtpr r31, <EV6__MM_STAT ! ^x50>
PALcode Restrictions and Guidelines
D–20
r20, ^x3301(r31)
r31, r31, r31
r31, r31, r31
r4, #13, r6
r6, #EV6__DTB_PTE0__PFN__S, r6
r6, r20, r6
r31, r31, r31
r31, r31, r31
r31, r31, r31
r6, ^x00(r4)
r6, ^x08(r4)
r6, ^x10(r4)
r6, ^x18(r4)
r6, ^x20(r4)
r6, ^x28(r4)
r6, ^x30(r4)
r6, ^x38(r4)
r6, ^x38(r4)
r6, r31, r6
r6, sys__crd_scrub_done
r31, .-4
r7, sys__cbox
r31, r31, r31
r31, r31, r31
r31, r31, r31
r31, r31, r31
r31, #1, r7
r7, #EV6__HW_INT_CLR__CR__S, r7 ; shift into position
r7, EV6__DC_STAT_W1C_CRD(r31)
r31, r31 ,r31
r31, r31 ,r31
; (7,1L) flush dtb
; set WE, RE
; wait for retire
; shift byte offset
; shift into position
; produce pte
; (2&6,0L) write tag0
; (1&5,1L) write tag1
; (0&4,0L) write pte0
; (3&7,1L) write pte1
; quiet before we start
; re-read the bad block QW #0
; re-read the bad block QW #1
; re-read the bad block QW #2
; re-read the bad block QW #3
; re-read the bad block QW #4
; re-read the bad block QW #5
; re-read the bad block QW #6
; no other mem-ops till done
; re-read the bad block QW #7
; now store it to force scrub
; consumer of above
; these 2 lines......
; .....stop pre-fetching
; clean the cbox error chain
; (7,1L) flush dtb
; wait for retire
; get a 1
; (4,0L) clear crd
; W1C bits
; (6,0L)
; stall till they retire
Alpha 21264/EV67 Hardware Reference Manual