Altera Avalon UART Speed Increase

1 -If you configure the UART such as to have a run-time programmable baud rate, you can program a divisor into the divisor register after power-up. See this document:

http://www.altera.com/literature/hb/nios2/n2cpu_nii51010.pdf

There are two other options I can think of which would obviously be unsupported:

2 - Edit the "class.ptf" file found at "C:\altera\90\ip\altera\sopc_builder_ip\altera_avalon_uart". Look for this description for the baud combo box:

                     COMBO baud
                     {
                        title = "Baud Rate (bps): ";
                        id="baud";
                        values="115200,57600,38400,31250,28800,19200,14400,9600,4800,2400,1200,300";
                        editable = "1";
                        DATA 
                        {
                           baud = "$";
                        }
                     }

Then obviously modify the values line to add your desired baud rate in there. I can't promise this is going to work. You may also have to modify the accompanying "em_uart.pl" perl script. Just do a search on baud in that file and you'll see where to modify it.

3 - The final option is to generate your SoPC system with the undesired baud rate. Then hand modify the generated HDL file to change the divisor. There should be a line somewhere like "assign divisor_constant = X" where you would calculate and replace X with the correct divisor rate.

Have fun,

Jake