VHDL PDP11

On Nov 12, 2011, at 11:29 AM, Jochen Kunz wrote: If you want a micro with built-in Ethernet, there are dozens. However, ones with built-in PHYs are even better because then all you need to do is deal with the magnetics (get a jack with built-in magnetics and you're set). TI's Stellaris series has one, and if you wanted to go the 68K route, Freescale's Coldfire MCF52235 is a 68k-esque implementation with a built-in PHY as well. Both are 10/100 and should significantly outperform the DELQA (12.5 MB/s should honestly be more than the PDP-11 can deal with effectively). The ARM open-source dev tools are honestly a bit nicer to work with than the Coldfire ones, so I'd recommend going that route. Both can be interfaced via SPI, which is really simple to make a bus interface with in HDL. You should be able to make a simple SPI interface that does the necessary actions of Unibus/QBUS, such as address masking and bus error/timeout detection. For SPI, you'd probably need to either do the address masking on the SPI part or have a fixed chip select mapping on the FPGA. If you wanted to be authentic, you could always make a MAC in the FPGA and go straight to AUI, but that would require you to develop your own AUI drivers (since most if not all of those driver chips aren't manufactured anymore). That's one option I have planned for my board. - Dave