How do I configure the Video Timing Controller to de-assert VBLANK at the same time as the HBLANK at the end of the last line of the frame?
Setting VBLANK to de-assert at the same time as HBLANK on the last line of the frame is not supported.
The way that the settings for the Video Timing Controller work is that the user defines the active region (H Active, V Active Size) and the full frame size (H Frame Size, V Frame Size).
Based on this, the IP will extrapolate the blank timing.
The controls available to the user are (GENERATOR F0_VBLANK_H - 0x007C):
The typical use case is for VBLANK to de-assert at the same time HBLANK asserts. However, the closest possible configuration to this is still off by 1 clock cycle.
You can configure the VBLANK to de-assert one clock cycle before HBLANK de-asserts on the last line of the frame. This is done by setting the Vblank End (F0_VBLANK_HEND) = HFRAME_SIZE - 1.