Baremetal / Arty Documentation

[samchin]

Right now, there is minimal documentation for the baremetal / Arty board. It would be nice if there were some.

Useful links:

https://github.com/bunnie/artybio-loader
https://github.com/betrusted-io/xous-core/blob/baremetal/baremetal/src/main.rs
https://github.com/betrusted-io/xous-core/tree/baremetal/utralib/artybio
https://digilent.com/reference/programmable-logic/arty-a7/reference-manual

[samchin]

LED Exercises

Adding a new RGBLED

As written, this line makes LD2 and LD3 exhibit colour-changing behaviour.

xous-core/baremetal/src/main.rs

Line 79 in 1bff1ee

rgb.wfo(utra::rgb::OUT_OUT, ((count / 500) as u32) << 6);

• Changing this to 3 instead of 6 adds LD1 so that LD1, LD2, LD3 exhibit colour-changing behaviour. rgb.wfo(utra::rgb::OUT_OUT, ((count / 500) as u32) << 3);

• Changing the code to this this code to makes LD0 exhibit colour-changing behaviour rgb.wfo(utra::rgb::OUT_OUT, ((count / 500) as u32) % 8);

• We can set LD1 as white while maintaining whatever else is going onrgb.wo(utra::rgb::OUT, rgb.r(utra::rgb::OUT) | 0b111000);

• We can also set LD2 directly as blue and turn off everything else rgb.wfo(utra::rgb::OUT_OUT, 0b100000000);

Reference

Arty LED Configuration

Artybio RGB Description

xous-core/utralib/src/generated/artybio.rs

Lines 288 to 295 in 1bff1ee

	pub mod rgb {
	pub const RGB_NUMREGS: usize = 1;
	pub const OUT: crate::Register = crate::Register::new(0, 0xfff);
	pub const OUT_OUT: crate::Field = crate::Field::new(12, 0, OUT);
	pub const HW_RGB_BASE: usize = 0xf0000000;
	}

Each location in the register refers to one of the RGB LEDs.

Mapping of Arty to RGB field input

   LD3 | LD2 | LD1 | LD0
   BGR | BGR | BGR | BGR 
0b 000   000   000   000