SMSC LAN9311 User Manual

Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

SMSC LAN9311/LAN9311i

19

Revision 1.4 (08-19-08)

 

 describes the register bit attribute notation used throughout this document.

Many of these register bit notations can be combined. Some examples of this are shown below:

„

R/W: Can be written. Will return current setting on a read.

„

R/WAC: Will return current setting on a read. Writing anything clears the bit.

R

Read: A register or bit with this attribute can be read.

W

Read: A register or bit with this attribute can be written.

RO

Read only: Read only. Writes have no effect.

WO

Write only: If a register or bit is write-only, reads will return unspecified data.

WC

Write One to Clear: writing a one clears the value. Writing a zero has no effect

WAC

Write Anything to Clear: writing anything clears the value.

RC

Read to Clear: Contents is cleared after the read. Writes have no effect.

LL

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 
compatibility. The value of reserved bits is not guaranteed on a read.