Struct Csrs 

pub struct Csrs {
    pub tvec: i64,
    pub tcause: i64,
    pub tepc: i64,
    pub tval: i64,
    pub tpriv: Priv,
    pub ie: Word,
    pub ip: Word,
    pub tie: Word,
    pub ptbr: i64,
    pub scratch: i64,
}

The control and status registers.

Fields

tvec: i64

Trap vector base. Zero leaves traps fatal, which is the reset state.

tcause: i64

Cause of the last trap.

tepc: i64

Program counter saved on the last trap.

tval: i64

Value associated with the last trap.

tpriv: Priv

Privilege saved on the last trap.

ie: Word

Interrupt enable mask, one trit per source.

ip: Word

Interrupt pending mask, one trit per source.

tie: Word

Interrupt enable saved when the last trap was taken.

Taking a trap clears ie and stores the old value here; tret restores it. Without this a level-triggered source re-fires before the handler’s first instruction and the handler never runs.

ptbr: i64

Page table base. Zero disables translation.

scratch: i64

Scratch space for the handler.

Implementations

impl Csrs

pub fn read(&self, n: i64, current: Priv) -> Option<i64>

Reads a register by number. None if the number is not defined.

pub fn write(&mut self, n: i64, v: i64) -> Option<bool>

Writes a register by number.

Some(false) for a register that exists but is read-only, None for one that does not exist. Writing a read-only register is silently ignored rather than trapping, matching the way r0 discards writes.

pub fn pending_interrupt(&self) -> Option<Cause>

The interrupt to take, if any.

A source fires when it is both pending and enabled, which is a per-trit minimum: Kleene AND over the two masks (D-06). The lowest such trit wins, so a lower-numbered source has priority.

pub fn set_pending(&mut self, source: usize, on: bool)

Sets or clears one trit of the pending mask.

Trait Implementations

impl Clone for Csrs

fn clone(&self) -> Csrs

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Csrs

impl Debug for Csrs

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

Formats the value using the given formatter.

impl Default for Csrs

fn default() -> Csrs

Returns the “default value” for a type.

impl Eq for Csrs

impl PartialEq for Csrs

fn eq(&self, other: &Csrs) -> 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 StructuralPartialEq for Csrs