How many gates do I need?

[PgrAm]

I'm in the middle of designing a single board computer and there are two spots where I have decided to use an FPGA or CPLD (which one i'm not sure yet). The first application is as a video controller, this chip would have two main functions:
1) to read data from some SRAMs and generate an 256 color VGA video signal
2) to move data around to different memory locations in the SRAM or copy data into SRAM from a second bank of SRAM (a blitter)

the second application for a programmable logic device is to replace a bunch discrete logic chips, memory latches and stuff like that, it would also act as a keyboard controller and implement an rs232 serial interface, bank switching and it would also send data to the video controller.

First of all what would be better for this these applications an FPGA or CPLD? (I'm leaning toward CPLD)
Secondly how many gates/logic elements would I need approximately for each application?

 

[PgrAm]

Is 1600 gates enough for to make a blitter and vga signal generator? Because I just realized that XC9572XLs are really cheap and they integrate nicely with the rest of my design because of their 5 volt tolerance.

 

[mrflibble]

Short answer: you don't want the long answer. (*)

Medium length answer: Pick the fpga/cpld that you think is reasonable for your design, synthesize your design in ISE and check the resource usage. Short of that this will become a hand waving excercise real fast.




*) You may think you want it, but you don't.