Hello,
I'm working with a Gumstix Overo board, and a Gumstix Caspa camera board. I'm trying to extend the cable range by using a serializer/deserializer pair. The Overo board has onboard an omap 3530, and the Caspa camera has an Aptina MT9V032 image. The overo board brings the parallel ISP data lines directly out to a connector. When the camera is plugged in directly to the overo board via a 5cm flexi-cable, the video image is fine.
I've now extended this using a serializer/deserializer pair (ds90ub901/2), and it *mostly* works. The video is frame locked and appears good except for some obvious artifacts which appear as horizontal purple-ish lines mostly over the right hand side of the frame. The signals coming from the deserializer look good, and setup-and-hold times on the data lines look good on a scope.
Can anyone suggest anything I need to look closer at? The camera end uses a dedicated 26.6MHz oscillator to feed the camera. Therefore the ISP clock cam_xclka is not used, as the deserializer derives its clock from the serial stream, and generates a recovered PCLK. This is then fed into the ISP interface. I was wondering whether a slight frequency difference between cam_xclka and PCLK could cause problems?
Any ideas??
Thanks very much