Per the timing diagram in Section 36.2.7.1.1 of the OMAP-L138 Technical Reference Manual - Progressive CCD Raw Capture, the VPIF requires 369 clock cycles of frame blanking between the assertion of the raw_v_valid and raw_h_valid signals. This is an extraordinary amount of blanking. In fact it causes an issue with the Aptina MT9V024 (and '034) image sensors because this interval is derived from the horizontal blanking interval and is not directly configurable via a dedicated register setting. In order to meet the 369 clock cycle requirement of the OMAP-L138 VPIF, the horizontal blank for the MT9V024 (034) needs to be set to 369+23 = 392 clock cycles. This will yield a delay between the assertion of raw_v_valid and the first raw_h_valid of exactly 392 clocks. However, is also reduces the maximum frame rate of he image sensor by almost 30% from 60 to just over 42 frames per second.
My question is whether the VPIF on the OMCP-L138 has been characterized with values of frame blank less than 369.
Regards
David R. King
