diff options
| author | James Munns <[email protected]> | 2025-12-05 14:28:47 +0100 |
|---|---|---|
| committer | James Munns <[email protected]> | 2025-12-05 14:28:47 +0100 |
| commit | b252db845e19603faf528cf93fe0c44757a27430 (patch) | |
| tree | 99e646d17bed747df244dd607a15f5a67baa530a /examples/mcxa/src/bin/dma_interleave_transfer.rs | |
| parent | 6a1eed83b9df8ffa81b93860f530f5bb3252d996 (diff) | |
Move
Diffstat (limited to 'examples/mcxa/src/bin/dma_interleave_transfer.rs')
| -rw-r--r-- | examples/mcxa/src/bin/dma_interleave_transfer.rs | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/examples/mcxa/src/bin/dma_interleave_transfer.rs b/examples/mcxa/src/bin/dma_interleave_transfer.rs new file mode 100644 index 000000000..7876e8978 --- /dev/null +++ b/examples/mcxa/src/bin/dma_interleave_transfer.rs | |||
| @@ -0,0 +1,215 @@ | |||
| 1 | //! DMA interleaved transfer example for MCXA276. | ||
| 2 | //! | ||
| 3 | //! This example demonstrates using DMA with custom source/destination offsets | ||
| 4 | //! to interleave data during transfer. | ||
| 5 | //! | ||
| 6 | //! # Embassy-style features demonstrated: | ||
| 7 | //! - `TransferOptions::default()` for configuration (used internally) | ||
| 8 | //! - DMA channel with `DmaChannel::new()` | ||
| 9 | |||
| 10 | #![no_std] | ||
| 11 | #![no_main] | ||
| 12 | |||
| 13 | use embassy_executor::Spawner; | ||
| 14 | use embassy_mcxa::clocks::config::Div8; | ||
| 15 | use embassy_mcxa::dma::{DmaCh0InterruptHandler, DmaChannel}; | ||
| 16 | use embassy_mcxa::lpuart::{Blocking, Config, Lpuart, LpuartTx}; | ||
| 17 | use embassy_mcxa::{bind_interrupts, pac}; | ||
| 18 | use {defmt_rtt as _, embassy_mcxa as hal, panic_probe as _}; | ||
| 19 | |||
| 20 | // Bind DMA channel 0 interrupt using Embassy-style macro | ||
| 21 | bind_interrupts!(struct Irqs { | ||
| 22 | DMA_CH0 => DmaCh0InterruptHandler; | ||
| 23 | }); | ||
| 24 | |||
| 25 | const BUFFER_LENGTH: usize = 16; | ||
| 26 | const HALF_BUFF_LENGTH: usize = BUFFER_LENGTH / 2; | ||
| 27 | |||
| 28 | // Buffers in RAM | ||
| 29 | static mut SRC_BUFFER: [u32; HALF_BUFF_LENGTH] = [0; HALF_BUFF_LENGTH]; | ||
| 30 | static mut DEST_BUFFER: [u32; BUFFER_LENGTH] = [0; BUFFER_LENGTH]; | ||
| 31 | |||
| 32 | /// Helper to write a u32 as decimal ASCII to UART | ||
| 33 | fn write_u32(tx: &mut LpuartTx<'_, Blocking>, val: u32) { | ||
| 34 | let mut buf = [0u8; 10]; | ||
| 35 | let mut n = val; | ||
| 36 | let mut i = buf.len(); | ||
| 37 | |||
| 38 | if n == 0 { | ||
| 39 | tx.blocking_write(b"0").ok(); | ||
| 40 | return; | ||
| 41 | } | ||
| 42 | |||
| 43 | while n > 0 { | ||
| 44 | i -= 1; | ||
| 45 | buf[i] = b'0' + (n % 10) as u8; | ||
| 46 | n /= 10; | ||
| 47 | } | ||
| 48 | |||
| 49 | tx.blocking_write(&buf[i..]).ok(); | ||
| 50 | } | ||
| 51 | |||
| 52 | /// Helper to print a buffer to UART | ||
| 53 | fn print_buffer(tx: &mut LpuartTx<'_, Blocking>, buf_ptr: *const u32, len: usize) { | ||
| 54 | tx.blocking_write(b"[").ok(); | ||
| 55 | unsafe { | ||
| 56 | for i in 0..len { | ||
| 57 | write_u32(tx, *buf_ptr.add(i)); | ||
| 58 | if i < len - 1 { | ||
| 59 | tx.blocking_write(b", ").ok(); | ||
| 60 | } | ||
| 61 | } | ||
| 62 | } | ||
| 63 | tx.blocking_write(b"]").ok(); | ||
| 64 | } | ||
| 65 | |||
| 66 | #[embassy_executor::main] | ||
| 67 | async fn main(_spawner: Spawner) { | ||
| 68 | // Small delay to allow probe-rs to attach after reset | ||
| 69 | for _ in 0..100_000 { | ||
| 70 | cortex_m::asm::nop(); | ||
| 71 | } | ||
| 72 | |||
| 73 | let mut cfg = hal::config::Config::default(); | ||
| 74 | cfg.clock_cfg.sirc.fro_12m_enabled = true; | ||
| 75 | cfg.clock_cfg.sirc.fro_lf_div = Some(Div8::no_div()); | ||
| 76 | let p = hal::init(cfg); | ||
| 77 | |||
| 78 | defmt::info!("DMA interleave transfer example starting..."); | ||
| 79 | |||
| 80 | // Enable DMA interrupt (DMA clock/reset/init is handled automatically by HAL) | ||
| 81 | unsafe { | ||
| 82 | cortex_m::peripheral::NVIC::unmask(pac::Interrupt::DMA_CH0); | ||
| 83 | } | ||
| 84 | |||
| 85 | let config = Config { | ||
| 86 | baudrate_bps: 115_200, | ||
| 87 | ..Default::default() | ||
| 88 | }; | ||
| 89 | |||
| 90 | let lpuart = Lpuart::new_blocking(p.LPUART2, p.P2_2, p.P2_3, config).unwrap(); | ||
| 91 | let (mut tx, _rx) = lpuart.split(); | ||
| 92 | |||
| 93 | tx.blocking_write(b"EDMA interleave transfer example begin.\r\n\r\n") | ||
| 94 | .unwrap(); | ||
| 95 | |||
| 96 | // Initialize buffers | ||
| 97 | unsafe { | ||
| 98 | SRC_BUFFER = [1, 2, 3, 4, 5, 6, 7, 8]; | ||
| 99 | DEST_BUFFER = [0; BUFFER_LENGTH]; | ||
| 100 | } | ||
| 101 | |||
| 102 | tx.blocking_write(b"Source Buffer: ").unwrap(); | ||
| 103 | print_buffer(&mut tx, core::ptr::addr_of!(SRC_BUFFER) as *const u32, HALF_BUFF_LENGTH); | ||
| 104 | tx.blocking_write(b"\r\n").unwrap(); | ||
| 105 | |||
| 106 | tx.blocking_write(b"Destination Buffer (before): ").unwrap(); | ||
| 107 | print_buffer(&mut tx, core::ptr::addr_of!(DEST_BUFFER) as *const u32, BUFFER_LENGTH); | ||
| 108 | tx.blocking_write(b"\r\n").unwrap(); | ||
| 109 | |||
| 110 | tx.blocking_write(b"Configuring DMA with Embassy-style API...\r\n") | ||
| 111 | .unwrap(); | ||
| 112 | |||
| 113 | // Create DMA channel using Embassy-style API | ||
| 114 | let dma_ch0 = DmaChannel::new(p.DMA_CH0); | ||
| 115 | |||
| 116 | // Configure interleaved transfer using direct TCD access: | ||
| 117 | // - src_offset = 4: advance source by 4 bytes after each read | ||
| 118 | // - dst_offset = 8: advance dest by 8 bytes after each write | ||
| 119 | // This spreads source data across every other word in destination | ||
| 120 | unsafe { | ||
| 121 | let t = dma_ch0.tcd(); | ||
| 122 | |||
| 123 | // Reset channel state | ||
| 124 | t.ch_csr().write(|w| { | ||
| 125 | w.erq() | ||
| 126 | .disable() | ||
| 127 | .earq() | ||
| 128 | .disable() | ||
| 129 | .eei() | ||
| 130 | .no_error() | ||
| 131 | .ebw() | ||
| 132 | .disable() | ||
| 133 | .done() | ||
| 134 | .clear_bit_by_one() | ||
| 135 | }); | ||
| 136 | t.ch_es().write(|w| w.bits(0)); | ||
| 137 | t.ch_int().write(|w| w.int().clear_bit_by_one()); | ||
| 138 | |||
| 139 | // Source/destination addresses | ||
| 140 | t.tcd_saddr() | ||
| 141 | .write(|w| w.saddr().bits(core::ptr::addr_of_mut!(SRC_BUFFER) as u32)); | ||
| 142 | t.tcd_daddr() | ||
| 143 | .write(|w| w.daddr().bits(core::ptr::addr_of_mut!(DEST_BUFFER) as u32)); | ||
| 144 | |||
| 145 | // Custom offsets for interleaving | ||
| 146 | t.tcd_soff().write(|w| w.soff().bits(4)); // src: +4 bytes per read | ||
| 147 | t.tcd_doff().write(|w| w.doff().bits(8)); // dst: +8 bytes per write | ||
| 148 | |||
| 149 | // Attributes: 32-bit transfers (size = 2) | ||
| 150 | t.tcd_attr().write(|w| w.ssize().bits(2).dsize().bits(2)); | ||
| 151 | |||
| 152 | // Transfer entire source buffer in one minor loop | ||
| 153 | let nbytes = (HALF_BUFF_LENGTH * 4) as u32; | ||
| 154 | t.tcd_nbytes_mloffno().write(|w| w.nbytes().bits(nbytes)); | ||
| 155 | |||
| 156 | // Reset source address after major loop | ||
| 157 | t.tcd_slast_sda().write(|w| w.slast_sda().bits(-(nbytes as i32) as u32)); | ||
| 158 | // Destination uses 2x offset, so adjust accordingly | ||
| 159 | let dst_total = (HALF_BUFF_LENGTH * 8) as u32; | ||
| 160 | t.tcd_dlast_sga() | ||
| 161 | .write(|w| w.dlast_sga().bits(-(dst_total as i32) as u32)); | ||
| 162 | |||
| 163 | // Major loop count = 1 | ||
| 164 | t.tcd_biter_elinkno().write(|w| w.biter().bits(1)); | ||
| 165 | t.tcd_citer_elinkno().write(|w| w.citer().bits(1)); | ||
| 166 | |||
| 167 | // Enable interrupt on major loop completion | ||
| 168 | t.tcd_csr().write(|w| w.intmajor().set_bit()); | ||
| 169 | |||
| 170 | cortex_m::asm::dsb(); | ||
| 171 | |||
| 172 | tx.blocking_write(b"Triggering transfer...\r\n").unwrap(); | ||
| 173 | dma_ch0.trigger_start(); | ||
| 174 | } | ||
| 175 | |||
| 176 | // Wait for completion using channel helper method | ||
| 177 | while !dma_ch0.is_done() { | ||
| 178 | cortex_m::asm::nop(); | ||
| 179 | } | ||
| 180 | unsafe { | ||
| 181 | dma_ch0.clear_done(); | ||
| 182 | } | ||
| 183 | |||
| 184 | tx.blocking_write(b"\r\nEDMA interleave transfer example finish.\r\n\r\n") | ||
| 185 | .unwrap(); | ||
| 186 | tx.blocking_write(b"Destination Buffer (after): ").unwrap(); | ||
| 187 | print_buffer(&mut tx, core::ptr::addr_of!(DEST_BUFFER) as *const u32, BUFFER_LENGTH); | ||
| 188 | tx.blocking_write(b"\r\n\r\n").unwrap(); | ||
| 189 | |||
| 190 | // Verify: Even indices should match SRC_BUFFER[i/2], odd indices should be 0 | ||
| 191 | let mut mismatch = false; | ||
| 192 | unsafe { | ||
| 193 | for i in 0..BUFFER_LENGTH { | ||
| 194 | if i % 2 == 0 { | ||
| 195 | if DEST_BUFFER[i] != SRC_BUFFER[i / 2] { | ||
| 196 | mismatch = true; | ||
| 197 | } | ||
| 198 | } else if DEST_BUFFER[i] != 0 { | ||
| 199 | mismatch = true; | ||
| 200 | } | ||
| 201 | } | ||
| 202 | } | ||
| 203 | |||
| 204 | if mismatch { | ||
| 205 | tx.blocking_write(b"FAIL: Mismatch detected!\r\n").unwrap(); | ||
| 206 | defmt::error!("FAIL: Mismatch detected!"); | ||
| 207 | } else { | ||
| 208 | tx.blocking_write(b"PASS: Data verified.\r\n").unwrap(); | ||
| 209 | defmt::info!("PASS: Data verified."); | ||
| 210 | } | ||
| 211 | |||
| 212 | loop { | ||
| 213 | cortex_m::asm::wfe(); | ||
| 214 | } | ||
| 215 | } | ||
