RTL8208B-LF/RTL8208BF-LF
Datasheet
Reserved – Ignore the output of the RTL8208B(F)-LF when these bits are read.
MF Preamble Suppression – Management Frame Preamble Suppression is permanently set in the
RTL8208B(F)-LF, allowing subsequent MII management frames to be accepted, with or without the
standard preamble pattern. Only two preamble bits are required between successive management
commands, instead of the normal 32. However, a minimum of 32 preamble bits are required for the first
SMI read/write transaction after reset. One idle bit is required between any two management transactions
(as defined in the IEEE 802.3u spec). Reads of this bit will always return a ‘1’.
Auto-Negotiation Complete – Bit 5 will return a ‘1’ if the auto negotiation process has been completed
and the contents of registers 4 and 5 are valid.
Remote Fault – When the link partner detects a far-end fault, it sends a far-end indication stream pattern.
When the RTL8208B(F)-LF receives this pattern, it sets Reg1.4=1.
Auto-Negotiation Ability – The RTL8208B(F)-LF is capable of performing IEEE auto negotiation, and
will return a ‘1’ when bit 4 is read, regardless of whether or not the auto negotiation function has been
disabled.
Link Status – The RTL8208B(F)-LF will return a ‘1’ on bit 2 when the link state machine is in Link Pass,
indicating that a valid link has been established. Otherwise, it will return ‘0’. When a link failure occurs
after the link pass state has been entered, the Link Status bit will be latched at ‘0’ and will remain so until
the bit is read. After the bit is read, it becomes ‘1’ if the Link Pass state has been entered again.
Jabber Detect – The RTL8208B(F)-LF will return a ‘1’ on bit 1 if a jabber condition has been detected.
After the bit is read, or if the chip is reset, it reverts to ‘0’. This is for 10Base-T only. Jabber occurs when
a predefined excessively long packet is detected in 10Base-T mode. When the duration of TX_EN
exceeds the jabber timer (21ms), transmit and loopback functions are disabled and the COL LED starts
blinking. After TX_EN goes low for more than 500ms, the transmitter is re-enabled and the COL LED
stops blinking.
Extended Capability – The RTL8208B(F)-LF supports extended capability registers and will return a ‘1’
when bit 0 is read. Several extended registers have been implemented in the RTL8208B(F)-LF.
Single-Chip Octal 10/100-TX/FX PHY Transceiver
17
Track ID: JATR-1076-21 Rev. 1.3
REALTEK [ Realtek Semiconductor Corp. ]
