15
ICS1890
10Base-T Block Diagram
10Base-T
Manchester Encoder/Decoder
When the
ICS1890
is operating in the 10Base-T mode,
Manchester coding is used. When transmitting, nibbles from
the MII are converted to a serial bit stream and then Manchester
en-coded. When receiving, the Manchester encoded bit stream
is decoded and converted to nibbles for presentation to the
MII.
Clock Synthesis
A 2.5 MHz clock is synthesized for nibble wide transactions.
A 10 MHz clock is synthesized for serial transactions.
Clock Recovery
The PLL synchronizes on the MAC frame preamble and then
begins recovering data normally.
Idle Function
The Idle function is used to keep a 10Base-T link alive in the
absence of data transmission.
If no data traffic is transmitted for 16ms, a link pulse will be
transmitted. Link pulse transmission will continue every 16ms
until real data is transmitted.
Link Monitor
This function is used to qualify a 10Base-T link. If neither data
or a Link Pulse is received for 50 to 150ms, then the link is
considered down. This state is exited after data is received or
3 to 10 Link Pulses are received.
Summary of Contents for PHYceiver ICS1890
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