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[stnolting]

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[razzy34]

demo_gpio_irq uses firq channel 8. The following changes are needed in main.c to make it work:

//install_err += neorv32_rte_exception_install(RTE_TRAP_FIRQ_1, gpio_pin_change_irq_handler);
install_err += neorv32_rte_exception_install(RTE_TRAP_FIRQ_8, gpio_pin_change_irq_handler);

//install_err += neorv32_cpu_irq_enable(CSR_MIE_FIRQ1E);
install_err += neorv32_cpu_irq_enable(CSR_MIE_FIRQ8E);

[stnolting]

Seems like I have forgotten to update that example program...
Thanks for the hint! 👍

[morrademedo]

Hello,

I came across your team's project, and it looks very promising. I would love to learn more and contribute to its development. Could you recommend any FPGA kits to start testing with the NEORV32? I would greatly appreciate a little support as I get started, since I haven't worked with FPGAs since graduating from university, but I really enjoy the freedom these devices offer.

Thank you!

[stnolting]

Hey @morrademedo.

I came across your team's project, and it looks very promising. I would love to learn more and contribute to its development.

You're most welcome! :)

Could you recommend any FPGA kits to start testing with the NEORV32?

This really depends on what you would like to do - and on your budget of course 😅

At first, I would suggest using commercial toolchains as a starting point. All big FPGA vendors provide free versions of their tools and most of them are pretty intuitive and straightforward to use. Furthermore, they provide nice features like rtl viewers and powerful timing analyzers. In a second step you could try switching to open-source tools.

As far as the actual FPGAs/boards are concerned, I can only speak for myself.

I really like the Lattice ice40UP FPGAs - they are so tiny and quite cheap. Furthermore, their support by open-source toolchains is just excelent. Here are some boards: https://www.latticesemi.com/solutionsearch?qiptype=982db688d64345bbb3af29e62fee1dc3&active=board I really like the iceBreaker board and the Upduino. Furthermore, the IDE (Radiant) is very nice - it is very tiny, simple to understand and easy to use. The integrated simulator is also one of the best I have seen (in terms of user interaction).

AMD and Digilent make some very nice entry-level boards. I can highly recommend the Arty ones: https://digilent.com/reference/programmable-logic/arty-a7/start The Vivado IDE can be quite overwhelming at the beginning but from my point of view it is the most powerful commercial IDE.

Intel/Altera + Terasic also have a nice set of development boards that are packed with IO and peripherals: https://www.terasic.com.tw/cgi-bin/page/archive.pl?Language=English&CategoryNo=13
Quartus is easy to handle. I know a lot universities that use it as entry-level FPGA IDE.

FPGA boars are quite expensive when compared with microcontroller boards. However, there are also a lot of second-hand sources which are just fine - you do not need the latest stuff from the FPGA market.

You could also start with a simulation-only setup using GHDL or any other (free) simulator. But of course having a real board is much more fun! 😄