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Chapter 5: Interlaken PHY IP Core
5–9
Interfaces
March 2012
Altera Corporation
Altera Transceiver PHY IP Core
User Guide
f
For more information about
_hw.tcl
, files refer to the
Component Interface Tcl Reference
chapter in volume 1 of the
Quartus II Handbook
.
The following sections describe the signals in each interface.
Avalon-ST TX Interface
Table 5–6
lists the signals in the Avalon-ST TX interface.
Table 5–6. Avalon-ST TX Signals
Signal Name
Direction
Description
tx_parallel_data
<n>
[63:0]
Sink
Avalon-ST data bus driven from the FPGA fabric to the TX PCS.
tx_parallel_data
<n>
[64]
Sink
Indicates whether
tx_parallel_data
<n>
[63:0]
represents control
or data. When deasserted,
tx_parallel_data
<n>
[63:0]
is a data
word. When asserted,
tx_parallel_data
<n>
[63:0]
is a control
word.
The value of header synchronization bits[65:64] of the Interlaken word
identify whether bits[63:0] are a Framing Layer Control/Burst/IDLE
Control Word or a data word. The MAC must gray encode the header
synchronization bits. The value 2’b10 indicating Burst/IDLE Control
Word must be gray encoded to the value 1’b1 for
tx_parallel_data
<n>
[64]
. The value 2’b01 indicating data word
must be gray encoded to the value 1’b0 for
tx_parallel_data
<n>
[64]
.
tx_parallel_data
<n>
[65]
Sink
When asserted, indicates that
tx_parallel_data
<n>
[63:0]
is valid
and is ready to be written into the TX FIFO. When deasserted, indicates
that
tx_parallel_data
<n>
[63:0]
is invalid and is not written into
the TX FIFO.
The Interlaken MAC should gate
tx_parallel_data
<n>
[65]
based
on
tx_datain_bp
<n>
.
tx_ready
Source
When asserted, indicates that the TX interface has exited the reset
state and is ready for service. The
tx_ready
latency for the TX
interface is 0. A 0 latency means that the TX FIFO can accept data on
the same clock cycle that
tx_ready
is asserted if
tx_parallel_data[65]
(valid) is also asserted. The Interlaken MAC
must wait for
tx_parallel_data[65]
before initiating data transfer
on any lanes. The TX FIFO only captures input data from the Interlaken
MAC when
tx_ready
and
tx_parallel_data[65]
are both
asserted.
For more information about the Avalon-ST interface and the use of
ready signals, refer to the “Data Transfer with Backpressure” section in
the “Avalon Streaming Interfaces” chapter of the
Avalon Interface
S
pecifications
.
tx_datain_bp
<n>
Source
When asserted, indicates that Interlaken TX lane
<n>
interface is ready
to receive data for transmission. The latency on this Avalon-ST
interface is 0 cycles. The Interlaken MAC should drive
tx_parallel_data
<n>
[63:0]
as soon as
tx_ready
<n>
and
tx_sync_done
are asserted. The
tx_datain_bp
<n>
signal is
connected to the
~partialfull
of the TX FIFO, so that when
tx_datain_bp
<n>
is deasserted the TX FIFO is almost full and back
pressures the Interlaken MAC.