Compaq 21264 User Manual
Page 144
5–2
Internal Processor Registers
Alpha 21264/EV67 Hardware Reference Manual
Instruction VA format
IVA_FORM
0000 0111
5
RO
0L
3
Current mode
CM
0000 1001
4
RW
0L
3
Interrupt enable
IER
0000 1010
4
RW
0L
3
Interrupt enable and current mode
IER_CM
0000 10xx
4
RW
0L
3
Software interrupt request
SIRR
0000 1100
4
RW
0L
3
Interrupt summary
ISUM
0000 1101
—
RO
—
—
Hardware interrupt clear
HW_INT_CLR
0000 1110
4
WO
0L
—
Exception summary
EXC_SUM
0000 1111
—
RO
0L
3
PAL base address
PAL_BASE
0001 0000
4
RW
0L
3
Ibox control
I_CTL
0001 0001
4
RW
0L
3
Ibox status
I_STAT
0001 0110
4
RW
0L
3
Icache flush
IC_FLUSH
0001 0011
4
W
0L
—
Icache flush ASM
IC_FLUSH_ASM
0001 0010
4
WO
0L
—
Clear virtual-to-physical map
CLR_MAP
0001 0101
4, 5, 6, 7
WO
0L
—
Sleep mode
SLEEP
0001 0111
4, 5, 6, 7
WO
0L
—
Process context register
PCTX
01xn nnnn
1
4
W
0L
3
Process context register
PCTX
01xx xxxx
4
R
0L
3
Performance counter control
PCTR_CTL
0001 0100
4
RW
0L
3
Mbox IPRs
DTB tag array write 0
DTB_TAG0
0010 0000
2, 6
WO
0L
—
DTB tag array write 1
DTB_TAG1
1010 0000
1, 5
WO
1L
—
DTB PTE array write 0
DTB_PTE0
0010 0001
0, 4
WO
0L
—
DTB PTE array write 1
DTB_PTE1
1010 0001
3, 7
WO
0L
—
DTB alternate processor mode
DTB_ALTMODE
0010 0110
6
WO
1L
—
DTB invalidate all process (ASM = 0) DTB_IAP
1010 0010
7
WO
1L
—
DTB invalidate all
DTB_IA
1010 0011
7
WO
1L
—
DTB invalidate single (array 0)
DTB_IS0
0010 0100
6
WO
0L
—
DTB invalidate single (array 1)
DTB_IS1
1010 0100
7
WO
1L
—
DTB address space number 0
DTB_ASN0
0010 0101
4
WO
0L
—
DTB address space number 1
DTB_ASN1
1010 0101
7
WO
1L
—
Memory management status
MM_STAT
0010 0111
—
RO
0L
3
Mbox control
M_CTL
0010 1000
6
WO
0L
—
Dcache control
DC_CTL
0010 1001
6
WO
0L
—
Dcache status
DC_STAT
0010 1010
6
RW
0L
3
Table 5–1 Internal Processor Registers (Continued)
Register Name
Mnemonic
Index
(Binary)
Score-
Board
Bit
Access
MT/MF
Issued
from Ebox
Pipe
Latency
for
MFPR
(Cycles)