Altera Embedded Peripherals IP - Manual (Page 187)

Operation—Avalon-ST Packets to Bytes Converter Core
The Avalon-ST Packets to Bytes Converter core receives packetized data and transforms the packets to
bytestreams. The core constructs outgoing bytestreams by inserting appropriate special characters in the
following manner and sequence:
• If the
startofpacket
signal on the core's source interface is asserted, the core inserts the following
special characters:
• Channel number indicator (
0x7c
).
• Channel number, escaping it if required.
• Start of packet (
0x7a
).
• If the
endofpacket
signal on the core's source interface is asserted, the core inserts an end of packet
(
0x7b
) before the last byte of data.
• If the
channel
signal on the core’s source interface changes to a new value within a packet, the core
inserts a channel number indicator (
0x7c
) followed by the new channel number.
• If a data byte is a special character, the core inserts an escape (
0x7d
) followed by the data XORed with
0x20
.
Document Revision History
Table 19-2: Document Revision History
Date and Document
Version
Changes Made Summary of Changes
July 2014
v14.0.0 -Removed mention of SOPC Builder, updated
to Qsys
Maintenance Release
December 2010
v10.1.0 Removed the “Device Support”, “Instantiating
the Core in SOPC Builder”, and “Referenced
Documents” sections.
—
July 2010
v10.0.0 No change from previous release. —
November 2009
v9.1.0 No change from previous release. —
March 2009
v9.0.0 No change from previous release. —
November 2008
v8.1.0 Changed to 8-1/2 x 11 page size. No change to
content.
—
May 2008
v8.0.0 Initial release. —
UG-01085
2014.24.07
Operation—Avalon-ST Packets to Bytes Converter Core 19-3
Avalon-ST Bytes to Packets and Packets to Bytes Converter Cores Altera Corporation
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