example dma

examples/rp/src/bin/dma_continuous.rs

@@ -0,0 +1,67 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_rp::dma::{self, ContinuousTransfer};
+use embassy_rp::pac::dma::vals::TreqSel;
+use embassy_rp::Peripheral;
+use embassy_time::{Duration, Instant, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let p = embassy_rp::init(Default::default());
+
+    let mut dma0 = p.DMA_CH0.into_ref();
+    let mut dma1 = p.DMA_CH1.into_ref();
+
+    loop {
+        let mut from_buf = [0u32; 300];
+
+        for (i, x) in from_buf.iter_mut().enumerate() {
+            *x = (2 - i as u32 / 100) * 100 + i as u32 % 100 + 1;
+        }
+
+        let mut control_input = [[0u32; 4]; 2];
+
+        let mut to_buf0 = [0u32; 100];
+        let mut to_buf1 = [0u32; 100];
+        let mut to_buf2 = [0u32; 100];
+
+        let start = Instant::now();
+        let mut cdma = ContinuousTransfer::start_new(
+            dma0.reborrow(),
+            dma1.reborrow(),
+            &mut control_input,
+            &mut to_buf2,
+            TreqSel::PERMANENT,
+            dma::Read::Increase(&from_buf),
+        );
+        #[allow(unused_assignments)]
+        let mut in_time = true;
+        let mut n_in_time = 0;
+
+        (cdma, in_time) = cdma.next(&mut to_buf1).await;
+        if in_time {
+            n_in_time += 1;
+        };
+
+        (cdma, in_time) = cdma.next(&mut to_buf0).await;
+        if in_time {
+            n_in_time += 1;
+        };
+
+        cdma.stop().await;
+        let time = Instant::now().duration_since(start);
+        info!("time: {} µs", time.as_micros());
+
+        info!("n_in_time {} out of 2", n_in_time);
+        info!("{}", to_buf0);
+        info!("{}", to_buf1);
+        info!("{}", to_buf2);
+
+        Timer::after(Duration::from_secs(1)).await;
+    }
+}