Altera SerialLite II Protocol - Manual (Page 45)

Altera Corporation 45
SerialLite II Protocol Reference Manual
SerialLite II Specification
7. Link management packets can only be followed by IDL in the same
column.
8. IDL characters are allowed to span entire columns and fill
inter-packet gaps.
9. Different payload packet types (between data, priority, and link
management packets) cannot share columns.
10. {SUP}, {EGP}, and {EBP} can share the same column as {SPP}, {SDP},
{CPP}, and {CDP}.
Data Transmission Rules
The following data transmission rules must be followed:
1. Data packets can be interrupted on a column boundary, and IDL
characters are transmitted in response to flow control requests
(
“Flow Control (Optional)” on page 2–61 ), or user interface
under-runs.
2. Priority packets can be interrupted on a segment size boundary, and
IDL characters are transmitted in response to flow control requests
(
“Flow Control (Optional)” on page 2–61 ), or user interface
under-runs.
3. Link management packets can be inserted on any column boundary
for both priority and data packets.
4. If packets are nested, the nested packet cannot share a column with
the interrupted data. Meaning that the interrupting packet must be
started on a new column. Once the nested packet is complete, the
interrupted packet must resume on a new column.
5. When data partially fills a column at the end-of-packet, the gap
must be filled with /IDL/ characters. /IDL/ bytes used for padding
and visible to the user are replaced with all zeros.
6. The CRC calculation only covers columns containing user data.
Lane Alignment Examples
For the examples in this section, a column of data aligned across all lanes
during a particular character cycle is shown pictorially as a row.
Switching between control and data can occur in every column.