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//! Application Program Status Register

/// Application Program Status Register
#[derive(Clone, Copy, Debug)]
pub struct Apsr {
    bits: u32,
}

impl Apsr {
    /// Returns the contents of the register as raw bits
    pub fn bits(&self) -> u32 {
        self.bits
    }

    /// DSP overflow and saturation flag
    pub fn q(&self) -> bool {
        self.bits & (1 << 27) == (1 << 27)
    }

    /// Overflow flag
    pub fn v(&self) -> bool {
        self.bits & (1 << 28) == (1 << 28)
    }

    /// Carry or borrow flag
    pub fn c(&self) -> bool {
        self.bits & (1 << 29) == (1 << 29)
    }

    /// Zero flag
    pub fn z(&self) -> bool {
        self.bits & (1 << 30) == (1 << 30)
    }

    /// Negative flag
    pub fn n(&self) -> bool {
        self.bits & (1 << 31) == (1 << 31)
    }
}

/// Reads the CPU register
///
/// **NOTE** This function is available if `cortex-m` is built with the `"inline-asm"` feature.
#[inline]
pub fn read() -> Apsr {
    match () {
        #[cfg(cortex_m)]
        () => {
            let r: u32;
            unsafe {
                asm!("mrs $0, APSR" : "=r"(r) ::: "volatile");
            }
            Apsr { bits: r }
        }

        #[cfg(not(cortex_m))]
        () => unimplemented!(),
    }
}