Struct RegisterAttribution 

pub struct RegisterAttribution { /* private fields */ }

Last write to each of $4000-$4017, with its cause.

Last write, not a history. One slot per address rather than a ring, because the question this half answers is “what is the register holding, and who put it there” — and a ring would need a retention policy nobody has a principled value for. The Event Viewer already keeps the per-frame write sequence; this keeps the per-register cause, which it does not.

Implementations

impl RegisterAttribution

pub const fn new() -> Self

A fresh table with every slot unwritten.

pub fn clear(&mut self)

Forget every recorded write.

pub const fn record(&mut self, addr: u16, pc: u16, cycle: u64, value: u8)

Record a write to addr. Addresses outside $4000-$4017 are dropped rather than wrapping into an unrelated slot.

pub const fn record_reset(&mut self, addr: u16, cycle: u64, value: u8)

Record a write performed by the APU’s own reset sequence.

Overwrites whatever Self::record just stored for the same address, which is deliberate: Apu::reset reaches the slot through the ordinary write_register path, so the honest origin has to replace the instruction attribution that path installs. The value and cycle are genuine — the register really did change, at that time — and only the claim about who caused it is corrected.

pub const fn get(&self, addr: u16) -> Option<RegWrite>

The last write to addr, or None if the address is out of range or nothing has written it since the last Self::clear.

Trait Implementations

impl Clone for RegisterAttribution

fn clone(&self) -> RegisterAttribution

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RegisterAttribution

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

Formats the value using the given formatter.

impl Default for RegisterAttribution

fn default() -> Self

Returns the “default value” for a type.