Forum Discussion
Altera_Forum
Honored Contributor
20 years agoHi fmcmurra,
> but for some reason it I don't get anything out of the UART (not JTAG UART). > I single steped through the code and it appears to be in the main loop waiting > for input. Make sure your clock setting is correct (CONFIG_SYS_CLK_FREQ). For the 'standard' FPGA configuration this should be 80 MHz (since the 24 MHz external clock is routed to a PLL). In the old versions of quartus, this was obvious since the PLL was always on the main schematic (bdf file). The new versions support the PLL component in SOPC Builder -- so it's real easy to overlook. > Is there something else I should be doing, besides enabling it in the config file? Not really -- I believe the baudrate is fixed at 115200 for the standard configuration. You can try switching to the jtag uart -- if that works, your problem will be isolated to uart1 ... if it doesn't, there's probably another problem. > Is it safe to assume my FPGA doesn't have SRAM? I'm inclined to believe it does, > but wasn't enabled. Should I enable it? I don't think the eval board has any external SRAM. You can create an on chip RAM with SOPC Builder if you like. It looks like there's plenty of memory left in the standard configuration -- although it's not necessary for any of the Nios-II specific code in u-boot. Regards, --Scott