Enum FlashPrefetch 

pub enum FlashPrefetch {
    Off,
    On,
    IfCodeInOneBank,
    IfSingleBank,
}

Flash prefetch (FLASH_ACR.PRFTEN).

On the STM32G0B0/G0B1/G0C1 in dual-bank mode a code prefetch can fail on a branch or function call across the flash banks (“Prefetch failure when branching across flash memory banks”: ES0547 2.2.8, ES0548 2.2.10, ES0549 2.2.10; not fixed in silicon revisions A, Z and Y; the only workaround is prefetch off).

Variants

Off

Prefetch off.

On

Prefetch on. On a dual-bank device the caller vouches that no code branches across the flash banks.

When code must sit in both banks with prefetch on, keep the cross-bank calls to a few known entry points and route each through a function in RAM that clears PRFTEN, makes the call and sets PRFTEN again. The errata list no workaround; a trampoline that keeps prefetch on during the crossing is not covered.

IfCodeInOneBank

Prefetch on, unless the device runs in dual-bank mode and the program’s code (__stext..__etext of cortex-m-rt) reaches into bank 2; without the rt feature, off on a device in dual-bank mode.

For applications that want the prefetch on a dual-bank device. Only the program’s own code is checked, so not for a bootloader that jumps into an application in the other bank: that jump branches across the banks.

IfSingleBank

Prefetch on, unless the device runs in dual-bank mode (the default).

Safe for any program, bootloaders included. An application on a dual-bank device gets the prefetch back with FlashPrefetch::IfCodeInOneBank; it then sets it from its own code when it initializes the clocks.

Trait Implementations

impl Clone for FlashPrefetch

fn clone(&self) -> FlashPrefetch

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FlashPrefetch

impl Debug for FlashPrefetch

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

Formats the value using the given formatter.

impl Eq for FlashPrefetch

impl Format for FlashPrefetch

fn format(&self, f: Formatter<'_>)

Writes the defmt representation of self to fmt.

impl PartialEq for FlashPrefetch

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FlashPrefetch