Chirp/src/cpu/quirks.rs

51 lines
1.6 KiB
Rust

//! Controls the [Quirks] behavior of the CPU on a granular level.
/// Controls the quirk behavior of the CPU on a granular level.
///
/// `false` is Cosmac-VIP-like behavior
#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Quirks {
/// Super Chip: Binary ops in `8xy`(`1`, `2`, `3`) shouldn't set vF to 0
pub bin_ops: bool,
/// Super Chip: Shift ops in `8xy`(`6`, `E`) shouldn't source from vY instead of vX
pub shift: bool,
/// Super Chip: Draw operations shouldn't pause execution until the next timer tick
pub draw_wait: bool,
/// XO-Chip: Draw operations should wrap from bottom to top and side to side
pub screen_wrap: bool,
/// Super Chip: DMA instructions `Fx55`/`Fx65` shouldn't change I to I + x + 1
pub dma_inc: bool,
/// Super Chip: Indexed jump instructions should go to `adr` + v`a` where `a` is high nibble of `adr`.
pub stupid_jumps: bool,
}
impl From<bool> for Quirks {
fn from(value: bool) -> Self {
if value {
Quirks {
bin_ops: true,
shift: true,
draw_wait: true,
screen_wrap: false,
dma_inc: true,
stupid_jumps: true,
}
} else {
Quirks {
bin_ops: false,
shift: false,
draw_wait: false,
screen_wrap: false,
dma_inc: false,
stupid_jumps: false,
}
}
}
}
impl Default for Quirks {
fn default() -> Self {
Self::from(false)
}
}