Intel CONTROLLERS 413808 - Manual (Page 48)

Intel
®
413808 and 413812—Introduction
Intel ® 413808 and 413812 I/O Controllers in TPER Mode
Developer’s Manual October 2007
48 Order Number: 317805-001US
1.6 Terminology and Conventions
1.6.1 Representing Numbers
All numbers in this document can be assumed to be Base10 unless designated
otherwise. In text, numbers in Base16 are represented as “nnnH”, where the “H”
signifies hexadecimal. In pseudo code descriptions, hexadecimal numbers are
represented in the form 0x1234ABCD. Binary numbers are not explicitly identified but
are assumed when bit operations or bit ranges are used.
1.6.2 Fields
A reserved field is a field that may be used by an implementation. When the initial
value of a reserved field is supplied by software, this value must be zero. Software
should not modify reserved fields or depend on any values in reserved fields.
A read/write field can written to a new value following initialization. This field can
always be read to return the current value.
A read only field can be read to return the current value. Writes to read only fields are
treated as no-op operations and does not change the current value nor result in an
error condition.
A read/clear field can also be read to return the current value. A write to a read/clear
field with the data value of 0 causes no change to the field. A write to a read/clear field
with a data value of 1 causes the field to be cleared (reset to the value of 0). For
example, when a read/clear field has a value of F0H, and a data value of 55H is written,
the resultant field is A0H.
A read/set field can also be read to return the current value. A write to a read/set field
with the data value of 0 causes no change to the field. A write to a read/set field with a
data value of 1 causes the field to be set (set to the value of 1). For example, when a
read/set field has a value of F0H, and a data value of 55H is written, the resultant field
ia F5H.
A writeonce/readonly field can be written to a new value
once following initialization.
After the this write has occurred, the writeonce/readonly field treats all subsequent
writes as no-op operations and does not change the current value or result in an error
condition. The field can always be read to return the current value.