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rp/pio: allow wrap-around program loading

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execution wraps around after the end of instruction memory and wrapping
works with this, so we may as well allow program loading across this
boundary. could be useful for reusing chunks of instruction memory.
This commit is contained in:
pennae
2023-05-06 20:53:06 +02:00
parent 374c7513f9
commit b38d496d51
3 changed files with 11 additions and 13 deletions
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11
embassy-rp/src/pio.rs
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@ -855,13 +855,14 @@ impl<'d, PIO: Instance> Common<'d, PIO> {
{
let mut used_mask = 0;
for (i, instr) in instrs.enumerate() {
let addr = (i + start) as u8;
let mask = 1 << (addr as usize);
if self.instructions_used & mask != 0 {
return Err(addr as usize);
// wrapping around the end of program memory is valid, let's make use of that.
let addr = (i + start) % 32;
let mask = 1 << addr;
if (self.instructions_used | used_mask) & mask != 0 {
return Err(addr);
}
unsafe {
PIO::PIO.instr_mem(addr as usize).write(|w| {
PIO::PIO.instr_mem(addr).write(|w| {
w.set_instr_mem(instr);
});
}