Altera 40-Gbps Ethernet MAC and PHY MegaCore Function - Manual (Page 75)

40-100GbE IP Core RX Data Bus Without Adapters (Custom Streaming Interface)
The RX bus without adapters consists of five 8-byte words, or 320 bits, operating at a frequency above
315 MHz for the 100GbE IP core or two 8-byte words, or 128 bits, for the 40GbE IP core, nominally at
315 MHz. This bus drives data from the RX MAC to the RX client.
Figure 3-25: RX MAC to Client Interface Without Adapters
The custom streaming interface bus width varies with the IP core variation. In the figure, = 2 for the
40GbE IP core and = 5 for the 100GbE IP core.
RX Client
Logic
RX MAC
dout_d[*64-1:0]
dout_c[*8-1:0]
dout_first_data[-1:0]
dout_last_data[*8-1:0]
dout_payload[-1:0]
dout_runt_last_data[-1:0]
dout_fcs_error
dout_fcs_valid
dout_dst_addr_match[-1:0]
dout_valid
clk_rxmac
Table 3-6: Signals of the RX Client Interface Without Adapters
In the table, = 2 for the 40GbE IP core and = 5 for the 100GbE IP core.
Signal Name Direction Description
dout_d[*64-
1:0]
Output Received data and Idle bytes. In RX preamble pass-through mode, this
bus also carries the preamble.
dout_c[*8-
1:0]
Output Indicates control bytes on the data bus. Each bit of dout_c indicates
whether the corresponding byte of
dout_d
is a control byte. A bit is
asserted high if the corresponding byte on
dout_d
is an Idle byte or the
Start byte, and has the value of zero if the corresponding byte is a data
byte or, in preamble pass-through mode, a preamble or SFD byte.
dout_first_
data[-1:0]
Output Indicates the first data word of a frame, in the current
clk_rxmac
cycle.
In RX preamble pass-through mode, the first data word is the word
that contains the preamble. When the RX preamble pass-through
feature is turned off, the first data word is the first word of Ethernet
data that follows the preamble.
dout_last_
data[*8–1:0]
Output Indicates the final data byte of a frame, before the FCS, in the current
clk_rxmac
cycle.
3-28 40-100GbE IP Core RX Data Bus Without Adapters (Custom Streaming Interface)
UG-01088
2014.12.15
Altera Corporation Functional Description
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