Altera 100G Interlaken MegaCore Function User Manual
Page 65
Signal Name
Direction Width
(Bits)
Description
irx_num_
valid
Output
8
irx_num_valid[7:4]
specifies the number of valid 64-bit words in the
current packet in the current data symbol. The maximum value of
irx_num_valid[7:4]
is eight, because a data symbol on the 512 bit
wide data path has eight words (8 x 64 bits = 512 bits).
In valid cycles, the IP core sets the value of
irx_num_valid[7:4]
as
follows:
• 4’b1000: if all eight words contain valid data from the current
packet.
• 4’b0xxx: where xxx indicates the number of valid words that are
part of the current packet, if the number is less than eight. Data is
always MSB aligned (left aligned). For example, the value of 4’b0111
indicates that word 0 (bit [63:0]) is not valid.
In dual segment mode, if the value of
irx_num_valid[7:4]
is four or
less (but not zero), the IP core can hold
irx_num_valid[2]
high to
indicate the current data symbol also includes the first four 64-bit
words of a new packet. The only valid values for
irx_num_valid[3:0]
are 4'b0100 and 4'b0000.
When
irx_num_valid[3:0]
has the value of 4'b0100, the IP core also
holds
irx_sop[0]
high.
The IP core sets the value of
irx_num_valid
to zero in all non-valid
cycles.
irx_sop
Output
2
Indicates the current data symbol on
irx_dout_words
contains the
start of a packet (SOP). This signal has the following valid values:
• 2'b00—The current data symbol does not contain the start of a
packet.
• 2'b10— If
irx_sop[1]
has the value of 1, the start-of-packet aligns
with the most significant byte (byte 63) of the data.
• 2'b01— If
irx_sop[0]
has the value of 1, the start-of-packet aligns
with byte 31 of the data. This value is valid only in variations
configured in dual segment mode.
UG-01128
2015.05.04
100G Interlaken IP Core User Data Transfer Interface Signals
5-7
100G Interlaken MegaCore Function Signals
Altera Corporation