pll: add convergence test
@@ -74,4 +74,23 @@ mod tests {
assert_eq!(y, 0xc2);
assert_eq!(f, y);
}
+
+ #[test]
+ fn converge() {
+ let mut p = PLLState::default();
+ let f0 = 0x71f63049_i32;
+ let shift = 10;
+ let n = 31 << shift + 2;
+ let mut x = 0i32;
+ for i in 0..n {
+ x = x.wrapping_add(f0);
+ let (y, f) = p.update(x, shift);
+ if i > n / 4 {
+ assert_eq!(f.wrapping_sub(f0).abs() <= 1, true);
+ }
+ if i > n / 2 {
+ assert_eq!(y.wrapping_sub(x).abs() < 1 << 18, true);
+ }
+ }
+ }
}
