Enum Mmc3Revision 

pub enum Mmc3Revision {
    Sharp,
    Nec,
}

MMC3 IRQ-counter behaviour. Default is the Sharp (“new”) behaviour; the alternative suppresses the “reload to 0 asserts IRQ” behaviour.

Naming, corrected in v2.9.6. These two variants were documented as “Sharp MMC3A” and “NEC MMC3B”. MMC3.md says otherwise: the old or alternate behaviour belongs to the MMC3A and to non-Sharp MMC3B chips (“1 (Sharp MMC3B, MMC3C) or 2 (MMC3A, Non-Sharp MMC3B) to 256 scanlines”), and the NES 2.0 submapper for it is 4, not 1 (NES_2_0_submappers.md). The behaviour of each variant was always right; only the labels were wrong, together with the submapper mapping that followed them.

Variants

Sharp

Sharp MMC3B and MMC3C: reloading the IRQ counter to 0 asserts IRQ if IRQs are enabled, so a latch of 0 fires every scanline. Default.

Nec

NEC MMC3B and the MMC3A: the IRQ fires on the counter’s 1 -> 0 transition, so a latch of 0 stops IRQs. NES 2.0 submapper 4.

Trait Implementations

impl Clone for Mmc3Revision

fn clone(&self) -> Mmc3Revision

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Mmc3Revision

impl Debug for Mmc3Revision

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Mmc3Revision

fn default() -> Mmc3Revision

Returns the “default value” for a type.

impl Eq for Mmc3Revision

impl Hash for Mmc3Revision

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for Mmc3Revision

fn eq(&self, other: &Mmc3Revision) -> bool

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Mmc3Revision