While theoretically possible, it's a non-standard engineering task to infer both H and V sync from the Mac Plus's video signal alone, so unless you have designed the circuitry to do this, you may be in for a disappointment. It's not like TV, where a composite video signal purposefully embeds sync information along with the video.
But that's not all. Unless your FPGA implements the equivalent of a PLL, you will also need the raw ~8MHz (7.8336MHz, IIRC) pixel clock from the Plus.
Maybe you already knew all this, and have designed the circuitry accordingly. But I just wanted to make sure that you weren't naive.
As to the Plus, some details on its video circuitry (and other topics) are here: http://68kmla.org/files/classicmac2.pdf
But that's not all. Unless your FPGA implements the equivalent of a PLL, you will also need the raw ~8MHz (7.8336MHz, IIRC) pixel clock from the Plus.
Maybe you already knew all this, and have designed the circuitry accordingly. But I just wanted to make sure that you weren't naive.
As to the Plus, some details on its video circuitry (and other topics) are here: http://68kmla.org/files/classicmac2.pdf