Second- Operand- Address
PASN-d Bits* PASN Result Field Equals Translation
PASN-old 29 30 Performed PSTD-new AX-new LTD-new PKM-new SASN-new Yes 0 0 No PSTD-old AX-old LTD-old PKM-d SASN-d Yes 0 1 No PSTD-old AX-d LTD-old PKM-d SASN-d Yes 1 0 Yes STD-p AX-p LTD-p PKM-d SASN-d Yes 1 1 Yes STD-p AX-d LTD-p PKM-d SASN-d
No - 0 Yes STD-p AX-p LTD-p PKM-d SASN-d
No -1 Yes STD-p AX-d LTD-p PKM-d SASN-d
Summary of Actions: LOAD ADDRESS SPACE PARAMETERS (Part 1 of 2)
Second-Ope rand- SASN-d SASN-d Address Bits* SASN SASN Equals Equals Translation Authorization Result Field PASN-d SASN-old 29 31 Performed PerformedU SSTD-new Yes - - - No No PSTD-new No Yes 0 1 No No SSTD-old
No Yes 1 1 Yes No STD-s
No Yes - 0 Yes Yes STD-s No No -1 Yes No STD-s
No No - 0 Yes Yes STD-s
Explanation:
- Action in this case is the same regardless of the outcome of this
comparison or of the setting of this bit. * Second-operand-address bits:
29 Force ASN translation. 30 Use AX from first operand.
31 Skip secondary authority test. U SASN authorization is performed using ATO-s, ATl-s, and AX-new.
Summary of Actions: LOAD ADDRESS SPACE PARAMETERS (Part 2 of 2)
PASN-new
PASN-d
PASN-d PASN-d PASN-d PASN-d PASN-d
Chapter 10. Control Instructions 10-17

Programming Notes
1. Bits 29 and 31 in the second­
operand address are intended prima­ rily to provide improved
performance for those cases where
the associated action is unneces­
sary.
When bit 29 is set to zero, the
action of the instruction is based
on the assumption that the current
values for PSTD-old, LTD-old, and AX-old are consistent with PASH-old and that SSTD-old is consistent
with SASH-old. When this is not
the case, bit 29 should be set to
one.
Bit 31, when one, eliminates the SASH-authorization test. The
program may be able to determine in
certain cases that the SASH is authorized, either because of prior
use or because the AX being loaded
is authorized to access all address
spaces.
2. The SASH-translation and SASH­ authorization steps are not
performed when SASH-d is equal to PASH-d. This is consistent with
the action in SET SECONDARY ASN to
current primary (SSAR-cp), which does not perform the translation or ASH authorization.
3. See the figure "Summary of Abbrevi­
ations for LOAD ADDRESS SPACE PARAMETERS" for a listing of abbre­ viations used in this instruction
description. 10-18 System/370 Principles of Operation
Abbreviation for Control- Register Previous Subsequent Humber.Bit Contents Contents 1.0-31 PSTD-old PSTD-new 3.0-15 PKM-old PKM-new
3.16-31 SASH-old SASH-new 4.0-15 AX-old AX-new
4.16-31 PASH-old PASN-new 5.0-31 LTD-old LTD-new 7.0-31 SSTD-old SSTD-new First-Operand
Bit Positions Abbreviation 0-15 PKM-d
16-31 SASN-d 32-47 AX-d 48-63 PASN-d Abbreviation Used for
the Field When Accessed
as Part of
Field in ASN- Second-Table PASH SASN Entry Translation Translation
8-29 -ATO-s
32-47 AX-p -
48-59 -ATL-s
64-95 STD-p STD-s
96-127 LTD-p
_1 - The field i s not used in this
case.
1
Although the field is not used,
bits 97-103 are tested for zeros. Summary of Abbreviations for LOAD ADDRESS SPACE PARAMETERS