KSZ8841-16 Micrel Semiconductor, KSZ8841-16 Datasheet - Page 22

• Manufacturer Part Number: KSZ8841-16
• Description: Single-port Ethernet Mac Controller With Non-pci Interface
• Manufacturer: Micrel Semiconductor

Magic Packet
Magic Packet technology is used to remotely wake up a sleeping or powered off PC on a LAN. This is accomplished by
sending a specific packet of information, called a Magic Packet frame, to a node on the network. When a PC capable of
receiving the specific frame goes to sleep, it enables the Magic Packet RX mode in the LAN controller, and when t
controller receives a Magic Packet frame, it will alert the syst
Magic Packet is a standard feat
down modes including Magic Pa
Once the KSZ8841M has b
to the node for a specific data sequence, which indicates to
A Magic Packet frame must also meet the basic requirements for the LAN technology chosen, such as Source Address
(SA), Destination Address (DA), which may be the receiving station’s IEEE address or a multicast or broadcast address
and CRC.
The specific sequence consists of 16 duplications of the IEEE address of this node, with no breaks or interruptions. This
sequence can be located anywhere within the packet, but must be preceded by a synchronization stream. The
synchronization
6 bytes of FFh. The device will also accept a broadcast frame, as long as the 16 duplications of the IEEE address match
the address of the machine to be awakened.
EXAMPLE
If the IEEE address for a particular node on a network is 11h 22h, 33h, 44h, 55h, 66h, the LAN controller would be
scanning for the data sequence (assuming an Ethernet frame):
DESTINATION SOURCE – MISC - FF FF FF FF FF FF - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 -
11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 -
11 22 33 44 55 66 - 11 22 33 44
11 22 33 44 55 66 - MISC - CRC.
There are no further restrictions on a M
IPX packet. The frame may be bridged or routed across the
frame’s destination.
If the LAN controller scans a frame and does not find the specific sequence shown above, it discards the frame and takes
no further actio
management circuitry (assert the PMEN pin) to wake up the system.
Physical Layer Transceiver (PHY)
100BASE-TX Transmit
The 100BASE-TX transmit function performs parallel-to-serial conversion, 4B/5B coding, scrambling, NRZ-to-NRZI
conversion, and MLT3 encoding an
The circuitry starts
stream. The data and control stream is then converted into 4B/5B coding, followed by a scrambler. The serialized data is
further converted from NRZ-to-NRZI format, and then transmitted in MLT3 current output. An external 1% 3.01KΩ resistor
for the 1:1 transformer ratio sets the output current.
The output signal has a typical rise/fall time of 4ns and complies with the ANSI TP-PMD standard regarding amplitude
balance, overshoot, and timing jitter. The wave-shaped 10BASE-T output driver is also incorporated into the 100BASE-TX
driver.
100BASE-TX Receive
The 100BASE-TX receiver function performs adaptive equalization, DC restoration, MLT3-to-NRZI conversion, data and
November 2005
Micrel Confidential
stream allows the scanning state machine to be much simpler. The synchronization stream is defined as
n. If the KSZ8841M controller detects the data sequence, however, it then alerts the PC’s power
with a parallel-to-serial conversion, which converts the MII data from the MAC into a 125MHz serial bit
een put into Magic Packet Enable mode (WFCR[7]=1), it scans all incoming frames addressed
cket to conserve power and operate more efficiently.
ure integrated into the KSZ8841M. The controller implements multiple advanced power-
55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 - 11 22 33 44 55 66 -
d transmission.
agic Packet frame. For instance, the sequence could be in a TCP/IP packet or an
22
the controller this is a Magic Packet (MP) frame.
em to wake up.
network without affecting its ability to wake-up a node at the
KSZ8841-16/32 MQL/MVL
Rev 1.3
he LAN