Ah, the Lord Giveth and the Lord Taketh Away. P4 didn't have enough raw speed for camera applications but had MIPI CSI, S31 has enough raw speed but no CSI.
I imagine that most of these (like almost all embedded chips) are designed primarily for some specific customer or two, and then they dump them on the market generally on the off chance someone else wants them too now that they're essentially capitalized.
I'm actually wrong about S31. The cores are clocked lower than P4. And somehow I thought S31 is 250 MHz 16-bit DDR PSRAM but it's 8-bit only. So if you have an uncompressed video stream over CSI, there's just nowhere to buffer it.
