embassy/examples/rp/src/bin/pio_dma.rs
pennae cbc8871a0b rp: relocate programs implicitly during load
this removed the RelocatedProgram construction step from pio uses.
there's not all that much to be said for the extra step because the
origin can be set on the input program itself, and the remaining
information exposed by RelocatedProgram can be exposed from
LoadedProgram instead (even though it's already available on the pio_asm
programs, albeit perhaps less convenient). we do lose access to the
relocated instruction iterator, but we also cannot think of anything
this iterator would actually be useful for outside of program loading.
2023-07-28 19:33:02 +02:00

85 lines
2.3 KiB
Rust

//! This example shows powerful PIO module in the RP2040 chip.
#![no_std]
#![no_main]
#![feature(type_alias_impl_trait)]
use defmt::info;
use embassy_executor::Spawner;
use embassy_futures::join::join;
use embassy_rp::peripherals::PIO0;
use embassy_rp::pio::{Config, InterruptHandler, Pio, ShiftConfig, ShiftDirection};
use embassy_rp::{bind_interrupts, Peripheral};
use fixed::traits::ToFixed;
use fixed_macro::types::U56F8;
use {defmt_rtt as _, panic_probe as _};
bind_interrupts!(struct Irqs {
PIO0_IRQ_0 => InterruptHandler<PIO0>;
});
fn swap_nibbles(v: u32) -> u32 {
let v = (v & 0x0f0f_0f0f) << 4 | (v & 0xf0f0_f0f0) >> 4;
let v = (v & 0x00ff_00ff) << 8 | (v & 0xff00_ff00) >> 8;
(v & 0x0000_ffff) << 16 | (v & 0xffff_0000) >> 16
}
#[embassy_executor::main]
async fn main(_spawner: Spawner) {
let p = embassy_rp::init(Default::default());
let pio = p.PIO0;
let Pio {
mut common,
sm0: mut sm,
..
} = Pio::new(pio, Irqs);
let prg = pio_proc::pio_asm!(
".origin 0",
"set pindirs,1",
".wrap_target",
"set y,7",
"loop:",
"out x,4",
"in x,4",
"jmp y--, loop",
".wrap",
);
let mut cfg = Config::default();
cfg.use_program(&common.load_program(&prg.program), &[]);
cfg.clock_divider = (U56F8!(125_000_000) / U56F8!(10_000)).to_fixed();
cfg.shift_in = ShiftConfig {
auto_fill: true,
threshold: 32,
direction: ShiftDirection::Left,
};
cfg.shift_out = ShiftConfig {
auto_fill: true,
threshold: 32,
direction: ShiftDirection::Right,
};
sm.set_config(&cfg);
sm.set_enable(true);
let mut dma_out_ref = p.DMA_CH0.into_ref();
let mut dma_in_ref = p.DMA_CH1.into_ref();
let mut dout = [0x12345678u32; 29];
for i in 1..dout.len() {
dout[i] = (dout[i - 1] & 0x0fff_ffff) * 13 + 7;
}
let mut din = [0u32; 29];
loop {
let (rx, tx) = sm.rx_tx();
join(
tx.dma_push(dma_out_ref.reborrow(), &dout),
rx.dma_pull(dma_in_ref.reborrow(), &mut din),
)
.await;
for i in 0..din.len() {
assert_eq!(din[i], swap_nibbles(dout[i]));
}
info!("Swapped {} words", dout.len());
}
}