VPIF: color bar alternating artifacts

Hi,

In using L138 to capture the RGB565 parallel output from OV5640 (parallel (DVP) interface, line D[9..0]]), we got the image as shown in the figure below.

The correct image should be the “color bar” as shown on the right, and the actual image for the first l00 lines in shown in the uppermost part of the figure. Note that the display color was not set correctly in the image to reflect the real color of the sensor’s output, but this is not a major problem.

The output of OV5640 is configured to be 720P (1280×720) and the CCS Image Analyzer has been configured accordingly. The real problem is that

1. In the area of some color bars (2^nd, 3^rd, 6^th, etc.), the color doesn’t appear to be pure. The magnified view show alternating pixel color in these area, which also correspond to alternating values in the memory view.
2. A lesser problem is that the transition between color bars takes several pixels and is not the ideal 1-pixel sharp transition.

L138’s VPIF is configured to capture raw image, and register settings are shown in the second figure below. All combinations of PCLK, VSYNC and HSYNC polarity has been tested and none solved the problem.

Could anyone offer suggestions?

Paul