That would defeat the purpose of making the data transfer as fast as possible.
Plus, it isn't more pins than I'll be able to deal with ultimately. It's more pins than the ^#%$^% Development Kit has easily available.
The FPGA chip I want to use has 372 I/O pins available. But I don't want to start my project by developing a board for the complicated FPGA and then experiment with soldering it and the other components down. I want to buy a Development Kit which already has the FPGA soldered down, and which has a DDR2 chip, parallel flash, 10/100 enet phy, 2-line LCD screen, two serial flash, and various pushbuttons and LEDs connected to the FPGA. The Development Kit also has demonstration code reference designs which makes all those things work, especially the DDR2 memory and the etherent phy.
All that stuff, plus the 100 pin connector, the three six pin connectors and the two 24 pin connectors use up about 282 of the 372 pins, but in all those connectors there are only ~79 pins available to connect to things off the board -- and to get those I'll be running little twisted pair pigtails from various connectors (six different headers) instead of just plugging into a single port.
So, to begin with, I want to get the Development kit. Play with the demos. See that the FPGA interface to the DDR2 works. See that the FPGA interface to the enet PHY works. Put data in the Flash. Pull data out of the Flash. See the lights light, and the buttons push. Etc.
Then, I just want to build a board that connects the SE/30 PDS slot to the available I/O pins on the Development Kit. And with the SE/30 connected to the FPGA Development Kit, I can write really simple FPGA code at first, so that the SE/30 writing to an address in the slot space makes an LED come on or some such. Or pressing a button on the FPGA Development Kit causes a bit in memory in slot space to change, which the SE/30 can read. That kind of thing.
From there I can work up, until I can interface the SE/30 software/firmware to the demos on the Development Kit. Ultimately getting to the point where read and write commands for the Development Kit DDR2 Demo software are coming from the SE/30 PDS slot, instead of from the Test Bench code in the Demo.