Struct rp_pac::dma::regs::ChTransCount

#[repr(transparent)]
pub struct ChTransCount(pub u32);

DMA Channel 3 Transfer Count

Tuple Fields

0: u32

Implementations

impl ChTransCount

pub const fn count(&self) -> u32

28-bit transfer count (256 million transfers maximum). Program the number of bus transfers a channel will perform before halting. Note that, if transfers are larger than one byte in size, this is not equal to the number of bytes transferred (see CTRL_DATA_SIZE). When the channel is active, reading this register shows the number of transfers remaining, updating automatically each time a write transfer completes. Writing this register sets the RELOAD value for the transfer counter. Each time this channel is triggered, the RELOAD value is copied into the live transfer counter. The channel can be started multiple times, and will perform the same number of transfers each time, as programmed by most recent write. The RELOAD value can be observed at CHx_DBG_TCR. If TRANS_COUNT is used as a trigger, the written value is used immediately as the length of the new transfer sequence, as well as being written to RELOAD.

pub fn set_count(&mut self, val: u32)

28-bit transfer count (256 million transfers maximum). Program the number of bus transfers a channel will perform before halting. Note that, if transfers are larger than one byte in size, this is not equal to the number of bytes transferred (see CTRL_DATA_SIZE). When the channel is active, reading this register shows the number of transfers remaining, updating automatically each time a write transfer completes. Writing this register sets the RELOAD value for the transfer counter. Each time this channel is triggered, the RELOAD value is copied into the live transfer counter. The channel can be started multiple times, and will perform the same number of transfers each time, as programmed by most recent write. The RELOAD value can be observed at CHx_DBG_TCR. If TRANS_COUNT is used as a trigger, the written value is used immediately as the length of the new transfer sequence, as well as being written to RELOAD.

pub const fn mode(&self) -> TransCountMode

When MODE is 0x0, the transfer count decrements with each transfer until 0, and then the channel triggers the next channel indicated by CTRL_CHAIN_TO. When MODE is 0x1, the transfer count decrements with each transfer until 0, and then the channel re-triggers itself, in addition to the trigger indicated by CTRL_CHAIN_TO. This is useful for e.g. an endless ring-buffer DMA with periodic interrupts. When MODE is 0xf, the transfer count does not decrement. The DMA channel performs an endless sequence of transfers, never triggering other channels or raising interrupts, until an ABORT is raised. All other values are reserved.

pub fn set_mode(&mut self, val: TransCountMode)

When MODE is 0x0, the transfer count decrements with each transfer until 0, and then the channel triggers the next channel indicated by CTRL_CHAIN_TO. When MODE is 0x1, the transfer count decrements with each transfer until 0, and then the channel re-triggers itself, in addition to the trigger indicated by CTRL_CHAIN_TO. This is useful for e.g. an endless ring-buffer DMA with periodic interrupts. When MODE is 0xf, the transfer count does not decrement. The DMA channel performs an endless sequence of transfers, never triggering other channels or raising interrupts, until an ABORT is raised. All other values are reserved.

Trait Implementations

impl Clone for ChTransCount

fn clone(&self) -> ChTransCount

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for ChTransCount

fn default() -> ChTransCount

Returns the “default value” for a type.

impl PartialEq for ChTransCount

fn eq(&self, other: &ChTransCount) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ChTransCount

impl Eq for ChTransCount

impl StructuralPartialEq for ChTransCount