
7–6 Chapter 7: Interlaken PHY IP Core
Avalon-ST TX Interface
Altera Transceiver PHY IP Core November 2012 Altera Corporation
User Guide
Avalon-ST TX Interface
Table 7–4 lists the signals in the Avalon-ST TX interface.
Table 7–4. Avalon-ST TX Signals (Part 1 of 3)
Signal Name Direction Description
tx_parallel_data<n>[63:0]
Input
Avalon-ST data bus driven from the FPGA fabric to the TX PCS. This
input should be synchronized to the
tx_coreclkin
clock domain.
tx_parallel_data<n>[64]
Input
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]
. You can also tie header
synchronization bit[65] to
tx_parallel_data[64]
directly.
tx_parallel_data<n>[65]
Input
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. This signal is the data valid or write enable port of the TX
FIFO. This input must be synchronized to the
tx_coreclkin
clock
domain.
The Interlaken MAC should gate
tx_parallel_data<n>[65]
based
on
tx_datain_bp<n>
. Or, you can tie
tx_datain_bp<n>
directly to
tx_parallel_data<n>[65]
. For Quartus II releases before 12.0,
you must pre-fill the transmit FIFO so this pin must be 1’b1 when
tx_ready
is asserted, but before
tx_sync_done
is asserted to insert
the pre-fill pattern. Do not use valid data to pre-fill the transmit FIFO.
Use the following Verilog HDL assignment for Quartus II releases prior
to 12.0:
assign tx_parallel_data[65] =
(!tx_sync_done)?1'b1:tx_datain_bp[0];
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