Table 2-3. Priority Levels; Table 2-4. Other "Or" Instruction Hints; Table 2-5. Program Priority Register (Ppr32) - IBM A2 User Manual

User's Manual
A2 Processor

Table 2-3. Priority Levels

Rx PPR32[PRI]
31 001
1 010
6 011
2 100
5 101
3 110
7 111

Table 2-4. Other "or" Instruction Hints

Rx Mnemonic
27 yield
29 mdoio
30 mdoom

Table 2-5. Program Priority Register (PPR32)

Register Short Name:
Decimal SPR Number:
Initial Value:
Slow SPR:
Guest Supervisor Mapping:
Bits Field Name
32:42 ///
43:45 PRI
46:63 ///
CPU Programming Model
Page 76 of 864
A2 Hardware Priority with IUCR1[HIPRI] Setting
ISA Priority
00
very low a2low
low
medium low a2medium
medium a2high
medium high
high
very high
Reserved
Yes
Yes
Yes
PPR32
898
0x00000000000C0000
Y
Initial
Value
0x0 Reserved
0b011 Thread Priority
001 Very low (privileged).
010 Low.
011 Medium low.
100 Medium.
101 Medium high (privileged).
110 High (privileged).
111 Very high (hypervisor).
Access violations or writing a value of zero will result in a nop.
0x0 Reserved
01 10
a2low a2low
a2medium a2medium
a2high
a2high
Read Access:
Write Access:
Duplicated for Multithread:
Notes:
Scan Ring:
Description
Privileged
11
a2low yes
no
a2medium no
no
yes
yes
a2high hypv
Any
Any
Y
ccfg
Version 1.3
October 23, 2012