82546EB Datasheet, PDF (15/47 Pages) Intel Corporation – Dual Port Gigabit Ethernet Controller

Networking Silicon — 82546EB
Symbol
CBE[7:0]#
PAR
PAR64
FRAME#
IRDY#
TRDY#
STOP#
IDSEL#
DEVSEL#
VIO
Type
Name and Function
Bus Command and Byte Enables. Bus command and byte enable signals are
multiplexed on the same PCI pins. During the address phase of a transaction,
CBE[7:0]# define the bus command. In the data phase, CBE[7:0]# are used as byte
TS
enables. The byte enables are valid for the entire data phase and determine which byte
lanes contain meaningful data.
CBE0# applies to byte 0 (LSB) and CBE7# applies to byte 7 (MSB).
Parity. The Parity signal is issued to implement even parity across AD[31:0] and
CBE[3:0]#. PAR is stable and valid one clock after the address phase. During data
phases, PAR is stable and valid one clock after either IRDY# is asserted on a write
TS
transaction or TRDY# is asserted after a read transaction. Once PAR is valid, it remains
valid until one clock after the completion of the current data phase.
When the 82546EB controller is a bus master, it drives PAR for address and write data
phases, and as a slave device, drives PAR for read data phases.
Parity 64. The Parity 64 signal is issued to implement even parity across AD[63:32] and
CBE[7:4]#. PAR64 is stable and valid one clock after the address phase. During data
phases, PAR64 is stable and valid one clock after either IRDY# is asserted on a write
TS
transaction or TRDY# is asserted after a read transaction. Once PAR64 is valid, it
remains valid until one clock after the completion of the current data phase.
When the 82546EB controller is a bus master, it drives PAR64 for address and write
data phases, and as a slave device, drives PAR64 for read data phases.
Cycle Frame. The Frame signal is driven by the 82546EB device to indicate the
STS ^{beginning and length of an access and indicate the beginning of a bus transaction.}
While FRAME#
transaction is in
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continue.
FRAME#
is
de-asserted
when
the
Initiator Ready. Initiator Ready indicates the ability of the 82546EB controller (as bus
master device) to complete the current data phase of the transaction. IRDY# is used in
conjunction with the Target Ready signal (TRDY#). The data phase is completed on any
clock when both IRDY# and TRDY# are asserted.
STS
During the write cycle, IRDY# indicates that valid data is present on AD[63:0]. For a
read cycle, it indicates the master is ready to accept data. Wait cycles are inserted until
both IRDY# and TRDY# are asserted together. The 82546EB controller drives IRDY#
when acting as a master and samples it when acting as a slave.
Target Ready. The Target Ready signal indicates the ability of the 82546EB controller
(as a selected device) to complete the current data phase of the transaction. TRDY# is
used in conjunction with the Initiator Ready signal (IRDY#). A data phase is completed
on any clock when both TRDY# and IRDY# are sampled asserted.
STS
During a read cycle, TRDY# indicates that valid data is present on AD[63:0]. For a write
cycle, it indicates the target is ready to accept data. Wait cycles are inserted until both
IRDY# and TRDY# are asserted together. The 82546EB device drives TRDY# when
acting as a slave and samples it when acting as a master.
Stop. The Stop signal indicates the current target is requesting the master to stop the
STS
current transaction. As a slave, the 82546EB controller drives STOP# to request the
bus master to stop the transaction. As a master, the 82546EB controller receives
STOP# from the slave to stop the current transaction.
I
Initialization Device Select. The Initialization Device Select signal is used by the
82546EB as a chip select signal during configuration read and write transactions.
Device Select. When the Device Select signal is actively driven by the 82546EB, it
STS
signals notifies the bus master that it has decoded its address as the target of the
current access. As an input, DEVSEL# indicates whether any device on the bus has
been selected.
VIO. The VIO signal is a voltage reference for the PCI interface (3.3 V or 5 V PCI
signaling environment). It is used as the clamping voltage.
P
Note: An external resistor is required between the voltage reference and the VIO pin.
The target resistor value is 100 KΩ
Datasheet
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