AR# 61430

LogiCORE IP AXI4-Stream to Video Out v3.0 - Why does the AXI4-Stream to Video Out core fail to lock, when the TVALID is deasserted ('0') before TLAST is asserted ('1')?

Description

Why does the AXI4-Stream to Video Out core fail to lock when the TVALID is deasserted ('0') before TLAST is asserted ('1')?

Solution

When used in slave timing mode, the core currently expects regular blanking periods in order to achieve lock.

In most cases, a 'blanking' period is represented in AXI Stream protocol by tvalid being deasserted for several cycles after tlast is asserted.

When the blanking period occurs before tlast or in the middle of a line, the core might not lock.

Users must assert TLAST with the last pixel of the line.

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AR# 61430
Date 09/16/2014
Status Active
Type General Article
IP