
IBM32NPCXX1EPABBE66
Preliminary
IBM Processor for Network Resources
pnr261_2io.fm.06
August 14, 2000
PHY Bus Interface
Page 27 of 706
FYTSDAT
1
Output
SERDES Transmit Data
(Differential Pair)
When using the internal framer and the internal SERDES,
these signals provide the serial transmit data stream.
FYTSDAT
1
FYTSCLK
1
Input
SERDES Transmit Clock
(Differential Pair)
When using the internal framer and the internal SERDES, the
reference 155.52MHz clock is supplied on these signals. When
not in use, pull FYTSCLKP low and pull FYTSCLKN high.
FYTSCLK
1
FYRSDAT
1
Input
SERDES Receive Data
(Differential Pair)
When using the internal framer and the internal SERDES, the
recovered receive data is supplied on these signals. When not
in use, pull FYRSDATP low and pull FYRSDATN high.
FYRSDAT
1
FYRSCLK
1
Input
SERDES Receive Clock
(Differential Pair)
When using the internal framer and the internal SERDES, the
recovered 155.52MHz clock is supplied on these signals.
When not in use, pull FYRSCLKP low and pull FYRSCLKN
high.
FYRSCLK
1
FYDTCT
1
Input
PHY Carrier Detect
When using an external PHY, the PHY uses this signal to indi-
cate carrier detect. When using the internal framer, this signal
provides the deserializer lock detect signal, ELockDet, from
the deserializer.
FYDISCRD
1
Input
PHY Cell Discard
When using an external PHY, this signal causes the current
cell being received to be discarded. In this case it should only
be asserted for the duration of one of the 53 bytes of the ATM
cell. When using the internal framer, this signal provides the
optical/electrical module Loss-Of-Signal indication, LossSig.
Table 9: PHY Bus Signal Descriptions
(Page 3 of 3)
Signal Name
Quantity
Type
Function
Description
Note:
Because some of the PHY transmit I/Os are used for receive framer functions and vice versa, there are some restrictions on how
the interfaces can be used.
1. If the transmit path is using an external PHY and the receive path is using the internal framer, FYTPAR(1) will provide Out of Frame
(OOF) status to the framer and will not be available as a parity output. This is only a concern if the PHY uses a 16-bit data interface
and parity is being used.
2. If the receive path is using an external PHY and the transmit path is using the internal framer, FYRPAR(1) will provide OFPtxLPow
status to the framer and will not be available as a parity input. This is only a concern if the PHY uses a 16-bit data interface.
If the transmit path is using an external PHY and the receive path is using the internal framer, and the external PHY has a 16-bit data
interface, then the receive HDLC interface cannot be used. The three I/O for the RX HDLC interface will instead take on the function of
FYTDAT(15-13).