Description

The AXI VDMA S2MM (write) channel can exhibit behavior where the current video frame's first line appears as the previous video frame's last line after an SOF_EARLY error. 

This happens when there is a command pending inside the datamover and an SOF_EARLY error occurs (causing the data to be flushed). 

When the next frame comes in and the AXI VDMA tries to recover from the error, it picks up the pending command, but there is no associated data left (because it has been flushed). 

Therefore, the AXI VDMA writes the first line of the next frame using the pending commands address.

Note: This does not necessarily happen every time an SOF_EARLY error occurs, only when there is a pending command in the datamover.

Solution

This behavior will cease once another SOF_EARLY error happens or the core is reset.

This is a known issue discovered in v5.02.a of the core. 

It is scheduled to be resolved in v5.03.a of the core (ISE 14.3 design tools).

Linked Answer Records

Master Answer Records