
Advance Data Sheet
March 2000
DNC3X3825
Octal 10/100 Mbits/s Ethernet Transceiver Macrocell
21
4
Register Information
(continued)
Table 14. MR1—Status Register Bit Descriptions
* The format for the bit descriptions is as follows: the first number is the register number, the second number is the bit position in the register.
R = read.
Bit
*
Type
R
Description
1.15 (T4ABLE)
100Base-T4 Ability.
This bit will always be a 0.
0: Not able.
1: Able.
100Base-TX Full-Duplex Ability.
This bit will always be a 1.
0: Not able.
1: Able.
100Base-TX Half-Duplex Ability.
This bit will always be a 1.
0: Not able.
1: Able.
10Base-T Full-Duplex Ability.
This bit will always be a 1.
0: Not able.
1: Able.
10Base-T Half-Duplex Ability.
This bit will always be a 1.
0: Not able.
1: Able.
Reserved.
All bits will read as a 0.
Suppress Preamble.
When this bit is set to a 1, it indicates that the
DNC3X3825 accepts management frames with the preamble suppressed.
Autonegotiation Complete.
When this bit is a 1, it indicates the autonegotiation
process has been completed. The contents of registers MR4, MR5, MR6, and
MR7 are now valid. The default value is a 0. This bit is reset when autonegotia-
tion is started.
Remote Fault.
When this bit is a 1, it indicates a remote fault has been detected.
This bit will remain set until cleared by reading the register. The default is a 0.
Autonegotiation Ability.
When this bit is a 1, it indicates the ability to perform
autonegotiation. The value of this bit is always a 1.
Link Status.
When this bit is a 1, it indicates a valid link has been established.
This bit has a latching function: a link failure will cause the bit to clear and stay
cleared until it has been read via the management interface.
Jabber Detect.
This bit will be a 1 whenever a jabber condition is detected. It will
remain set until it is read, and the jabber condition no longer exists.
Extended Capability.
This bit indicates that the DNC3X3825 supports the
extended register set (MR2 and beyond). It will always read a 1.
1.14 (TXFULDUP)
R
1.13 (TXHAFDUP)
R
1.12 (ENFULDUP)
R
1.11 (ENHAFDUP)
R
1.10:7 (RESERVED)
1.6 (NO_PA_OK)
R
R
1.5 (NWAYDONE)
R
1.4 (REM_FLT)
R
1.3 (NWAYABLE)
R
1.2 (LSTAT_OK)
R
1.1 (JABBER)
R
1.0 (EXT_ABLE)
R