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Table 13: Sideband Signal Descriptions in pcie(n)_m_axis_rc_tuser (cont'd)
Bit Index
Name
Width
Description
37:34
is_eof_0[3:0]
4
End of a first Completion TLP and the offset of its last
Dword.
These outputs are used only when the interface width is 256
bits and the straddle option is enabled.
The assertion of the bit is_eof_0[0] indicates the end of a
first Completion TLP in the current beat. When this bit is set,
the bits is_eof_0[3:1] provide the offset of the last Dword of
this TLP.
41:38
is_eof_1[3:0]
4
End of a second Completion TLP and the offset of its last
Dword.
These outputs are used only when the interface width is 256
bits and the straddle option is enabled. The core can then
straddle two Completion TLPs in the same beat. These
outputs are reserved in all other cases.
The assertion of is_eof_1[0] indicates a second TLP ending in
the same beat. When bit 0 of is_eof_1 is set, bits [3:1]
provide the offset of the last Dword of the TLP ending in this
beat. Because the second TLP can only end at a byte
position in the range 27–31, is_eof_1[3:1] can only take one
of two values (6 or 7).
The offset for the last byte of the second TLP can be
determined from the starting address and length of the TLP,
or from the byte enable signals byte_en[31:0].
If
is_eof_1[0]
is High, the signals is_eof_0[0] and is_sof_1
are also High in the same beat.
42
discontinue
1
This signal is asserted by the core in the last beat of a TLP, if
it has detected an uncorrectable error while reading the TLP
payload from its internal FIFO memory. The user application
must discard the entire TLP when such an error is signaled
by the core.
This signal is never asserted when the TLP has no payload.
It is asserted only in the last beat of the payload transfer;
that is, when is_eof_0[0] is High.
When the straddle option is enabled, the core does not start
a second TLP if it has asserted discontinue in a beat.
When the core is configured as an Endpoint, the error is also
reported by the core to the Root Complex to which it is
attached, using Advanced Error Reporting (AER).
74:43
parity
32
Odd parity for the 256-bit transmit data.
Bit i provides the odd parity computed for byte i of
pcie(n)_m_axis_rc_tdata. Only the lower 16 bits are used
when the interface width is 128 bits, and only the lower 8
bits are used when the interface width is 64 bits. Bits [31:16]
are set permanently to 0 by the core when the interface
width is configured as 128 bits, and bits [31:8] are set
permanently to 0 when the interface width is configured as
64 bits.
512-bit Interfaces
This section provides the description for ports associated with the user interfaces of the core.
Chapter 3: Product Specification
PG346 (v3.3) November 16, 2022
CPM Mode for PCI Express
53