
IBM2520L8767
IBM Processor for ATM Resources
atmrm.chapt02.01
08/27/99
ATM PHY Bus Interface
Page 29 of 553
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PHY Bus Pin Descriptions
(Page 1 of 2)
Quantity
Pin Name
Input/Output
Pin Function
Pin Description
16
FYTDAT (15 - 0)
Output
PHY Transmit Data.
When using an external PHY, this 16 pin bus carries the ATM
CELL octets that are loaded in the PHY Transmit FIFO. When
using the internal framer, the lower eight bits carry the SONET/
SDH octets bound for the network, while bits 15, 14, and 13 are
used for the RX HDLC interface signals OFPrxR1Data,
OFPrxR1DS and OFPrxRclk, respectively.
2
FYTPAR (1 - 0)
Output
Transmit Data Parity.
When using an external PHY, these are byte parity signals for
FYTDAT. When using the internal framer, bit one provides the
RX Out-Of-Frame indication, OOF, and bit 0 provides the opti-
cal/electrical module transmit shutdown control signal, OFPtx-
SDown.
1
FYTSOC
Output
Transmit start of Cell.
When using an external PHY, this indicates the start of cell on
FYTDAT. When using the internal framer, this provides the TX
HDLC interface signal, OFPtxT1Dclk.
1
FYTWRB
Output
Transmit write strobe.
When using an external PHY, this signal is used to write ATM
cells to the transmit FIFO. When using the internal framer, this
signal provides the 19.44 MHz TX clock, RefClkT.
1
FYTENB
Output
Transmit write enable.
When using an external PHY, this indicates that transmit data
to the PHY is valid. When using the internal framer, this pro-
vides the TX HDLC interface signal, OFPtxT1DS. When inter-
facing to the IBM2520L8767, it should be connected to -TDVal.
1
FYRENB
Output
Receive write enable.
When using an external PHY, this indicates to the PHY that
the IBM2520L8767 is ready to accept data. When using the
internal framer, this provides the clock recovery reset signal,
RSTCRec1. When using the IBM ATM-TC PHY, this should be
connected to +RLoad.
1
FYRRDB
Output
Receive ready strobe.
When using an external PHY, this is used to read ATM cells
from the PHY receive FIFO. When using the internal framer,
this signal provides the 19.44 MHz RX clock, RxByClk. When
using the IBM ATM-TC (25 Mb/s), this should be connected to
RBCLK.
16
FYRDAT(15 - 0)
Input
PHY Receive Data .
When using an external PHY, this 16 pin bus carries the ATM
CELL octets that are read from the PHY Receive FIFO. When
using the internal framer, the lower eight bits carry the SONET/
SDH octets received from the network.
2
FYRPAR(1 - 0)
Input
PHY Receive Data Parity.
When using an external PHY, these are byte parity signals for
FYRDAT. When using the internal framer, bit 1 provides the
optical/electrical module low power indication signal, OFPtx-
LPow, and bit 0 is not used.
1
FYRSOC
Input
Receive start of Cell.
When using an external PHY, This signal indicates the start of
cell on the FYRDAT bus. When using the IBM ATM-TC phy,
this input should be pulled down to the inactive state. When
using the internal framer, this is the receive frame pulse input
signal, FPulse. indicates when a cell is available in the receive
FIFO. When using the internal framer, this signal is not used.
When using IBM ATM-TC, it should be connected to +RDVal.