KS8737 Micrel Inc, KS8737 Datasheet - Page 11

• Manufacturer Part Number: KS8737
• Manufacturer: Micrel Inc

Specifications of KS8737

• Lead Free Status / RoHS Status: Not Compliant

Error Signals: Whenever the KS8737 receives an error symbol from the network, it asserts RXER and drives “1110” (4B)
on the RXD pins. When the MAC asserts TXER, the KS8737 will drive “H” symbols out on the line.
Carrier Sense (CRS): For 100TX links, a start-of-stream delimiter, or /J/K symbol pair causes assertion of Carrier Sense
(CRS). An end-of-stream delimiter, or /T/R symbol pair causes de-assertion of CRS. The PMA layer will also de-assert CRS
if IDLE symbols are received without /T/R, yet in this case RXER will be asserted for one clock cycle when CRS is de-asserted.
For 10T links, CRS assertion is based on reception of valid preamble, and de-assertion on reception of an end-of-frame (EOF)
marker.
Collision: Whenever the line state is half-duplex and the transmitter and receiver are active at the same time, the KS8737
asserts its collision signal which is asynchronous to any clock.
Power Management
The KS8737 offers the following modes for power management:
Fiber Mode
Fiber mode is activated by setting FXMODEB (pin46) low. Under this mode, the FIBP/M are become the receiving port, and
the TXP/M are the transmit port. FXSD (+) and FXSD_THD (-) are used as differential signal for Fiber signal detect port. If driven
single-ended with FXSD and FXSD_THD should be set by an external voltage divider for the proper reference voltage, there
is no internal voltage for this pin.
Under Fiber mode, the link is up only when FXSD>FXSD_THD and the proper idle pattern is received. If FXSD<FXSD_THD,
then a Far-end-fault (FEF) pattern will be sent out. The link partner that receives FEF will have its link turn off. The link partner,
however, will still send the normal transmission while receiving FEF. This feature can be turned off by setting the Pin 17 low.
Media Converter Mode
The KS8737 provides a special fiber mode in which allows back-to-back FX to TX media conversion using two KS8737’s. This
special mode can be activated by pulling pin 32 high through an external 1k resistor. The detailed connection between the two
KS8737’s is shown in the application circuit on the data sheet. In this case TXC become an input pin. The internal FIFO’s will
take care of the transition of the receive to transmit clock domain changes. The KS8737 in media converter mode can also
handle the jumbo frames. The recovered clock and parallel data (RXC, RXD[0:3]) from the other chip will feed the chip through
TXC and TXD[0:3].
Under the Media Converter mode, the KS8737 support disable transmit feature by pull-up on DSITX/LPBK (pin 33) pin. For
more details, see
August 2003
KS8737
• Power Down Mode: This mode can be achieved by writing to Register 0.11 or pulling pin PWRDWN High.
• Power Saving Mode: This mode can be enabled by writing to Register 1fh.15. or using an external initialization pin.
The KS8737 will then turn off everything except for the Energy Detect and PLL circuits when the cable is not installed.
In other words, the KS8737 will shutdown most of the internal circuits to save power if there is no link.
"Pin Description”
section.
11
KS8737
Micrel