Ethernet or USB2.0 link to FPGA design question

Hello,

I am designing a device and I have thought on using a FPGA to build a bridge between computer and peripherals so it adapts any needed protocol (UART mainly, SPI, I2C) to the computer.

So, I need a high speed and high availability link from CPU to FPGA, which it can be:

a) USB2.0 device, I have checked with asics.ws (maintainer of USB2.0 IP Core) and they ask me for over $20000, which it is way out of budget. I have not enough knowledge to test and fix opencores.org core in the requested time. Do you have any idea on how to proceed this way with a tight budget? The idea would be to have built into FPGA a USB-to-{N-UART,SPI,I2C,..}


b) Ethernet, same approach as above but I am a bit worried about TCP/IP stack, if one needs the data from the packets, one must need processing power (Microblaze, embedded PPC,..) Am I right? Could I build a reliable ethernet connection picking up data without processing power (without need of a soft/hard processor)? Maybe you have somekind of FPGA with a builtin stack.



Do you have a better proposal to do this kind of communication?

My computer only has Ethernet, USB and SATA.



Kind regards

PLease see:

**broken link removed**

If you just want to do UART, SPI, or I2C to a computer, a microcontroller with an integrated USB controller will be a far, far easier option. Have you heard of the Bus Pirate? It does all of this and more.

If you're set on using an FPGA, a USB-serial bridge such as one of the devices made by FTDI Chip (e.g. the FT2232D) will save you a lot of work, if you only need serial communications to your PC.

Ethernet is also an option and it is definitely possible to implement it without any sort of soft processor, especially if you can get away with using just UDP. No FPGA I'm aware of includes a TCP/IP stack. Again, there are external modules (e.g. those made by WizNet) that will let you add Ethernet to your projects using a serial interface.

The best option will probably depend on a few other design requirements you haven't described, such as the exact bandwidth you require, the maximum physical distance between this device and your PC, the number of PCs that need to access the device simultaneously, etc.