Craddock, Chris wrote:
Can anyone tell me where I can find clear explanations and difference
between the following:
1.Home address
2.Primary address
3.Secondary address
Each address space is identified by a 16 bit number called the address
space identifier (ASID.) It is used by hardware during the translation
process and MVS also uses it as an index in various tables such as the
ASVT.
[loads of great info snipped]
A simplified way to answer the OP's question as stated:
1) A home address is one that is resolved by the region/segment/page
tables described by control register 13.
2) A primary address is one that is resolved by the region/segment/page
tables described by control register 1.
3) A secondary address is one that is resolved by the
region/segment/page tables described by control register 7.
Usually home=primary=secondary. The home address space is always that
which is dispatched by the operating system. Various instructions (e.g.,
PC, SSAR, etc.) are used to change the primary or secondary address
space to other than home.
POP explains the concepts in detail. Extended Addressability Guide does
a good job as well. Whether the explanations are clear is subjective and
depends entirely on how well you understand z/Architecture.
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