Microsemi FPGAs

We have done a couple of projects with them, and the tools haven't been bad to work with.

You start with a top level block diagram in which you place a block for the processor. There is a 'System Builder' tool that builds and configures the processor block and support logic around it (like adding in additional peripherals that are provided that aren't hard logic in the processor), which becomes a piece of your design, and then you add other blocks to represent other parts of your design (built with HDL, provided cores, or other block diagrams)). You can also just put down the symbol for the core MPU and build the stuff around it yourself if you need something a bit non-standard.

The one thing that is a bit frustrating is that block diagrams are 'auto-routed' and 'auto-placed' (auto-placing mostly on command), and the algorithms sometimes seem a bit strange. I find I tend to need to lock the major blocks so they don't go to strange places, and occasionally wish there was a similar option for the line.

The software side is Eclipse/GCC based and seems to run fairly cleanly. The only real issue I have seen is that the FPGA tools generate the Board Support Package files in a sub-directory of the FPGA design, and you need to copy those over to your Software Project directory as you hand them off between the team members.

They use Modelsim for the simulator and Synplify for synthesis. That's as good as it gets. Rest of the tools seem to be fine. I did a design with one of these parts last year - didn't come across anything particularly troublesome.

I didn't use the high level (Matlab/Simulink) based design tools so don't know how they compare to the Altera/Xilinx equivalents - I wouldn't expect them to be as capable as the latter.

They are. Lattice also offer good value on small/medium FPGA's (not SOC's) - I tend to use Lattice in preference to Altera/Xilinx.