LAN9250
1.3
Register Nomenclature
TABLE 1-3:
REGISTER NOMENCLATURE
Register Bit Type Notation
Register Bit Description
R
W
Read: A register or bit with this attribute can be read.
Read: A register or bit with this attribute can be written.
Read only: Read only. Writes have no effect.
RO
WO
WC
WAC
RC
LL
Write only: If a register or bit is write-only, reads will return unspecified data.
Write One to Clear: Writing a one clears the value. Writing a zero has no effect
Write Anything to Clear: Writing anything clears the value.
Read to Clear: Contents is cleared after the read. Writes have no effect.
Latch Low: Clear on read of register.
LH
Latch High: Clear on read of register.
SC
Self-Clearing: Contents are self-cleared after the being set. Writes of zero have no
effect. Contents can be read.
SS
Self-Setting: Contents are self-setting after being cleared. Writes of one have no
effect. Contents can be read.
RO/LH
Read Only, Latch High: Bits with this attribute will stay high until the bit is read. After it
is read, the bit will either remain high if the high condition remains, or will go low if the
high condition has been removed. If the bit has not been read, the bit will remain high
regardless of a change to the high condition. This mode is used in some Ethernet PHY
registers.
NASR
Not Affected by Software Reset. The state of NASR bits do not change on assertion
of a software reset.
RESERVED
Reserved Field: Reserved fields must be written with zeros to ensure future compati-
bility. The value of reserved bits is not guaranteed on a read.
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DS00001913B-page 7