Update lower VCO frequency limit according to datasheet update

Fixes rp-rs#682
jannic · Feb 22, 2024 · e47a59e · e47a59e
1 parent e175d2a
commit e47a59e
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diff --git a/rp2040-hal/CHANGELOG.md b/rp2040-hal/CHANGELOG.md
@@ -32,6 +32,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix USB PLL's VCO frequency according to updated datasheet - #688 @ithinuel, @jannic
 - Fix UART transmit\_flushed method - #713 @jannic
 - Fix calculation of pll frequency for refdiv != 1 - #691 @vinsynth
+- Fixed minimum PLL's VCO frequency according to updated datasheet - #684 @ithinuel
 
 ### Changed
 

diff --git a/rp2040-hal/src/pll.rs b/rp2040-hal/src/pll.rs
@@ -141,18 +141,22 @@ impl<D: PhaseLockedLoopDevice> PhaseLockedLoop<Disabled, D> {
         xosc_frequency: HertzU32,
         config: PLLConfig,
     ) -> Result<PhaseLockedLoop<Disabled, D>, Error> {
-        const VCO_FREQ_RANGE: RangeInclusive<HertzU32> = HertzU32::MHz(400)..=HertzU32::MHz(1_600);
+        const VCO_FREQ_RANGE: RangeInclusive<HertzU32> = HertzU32::MHz(750)..=HertzU32::MHz(1_600);
         const POSTDIV_RANGE: Range<u8> = 1..7;
         const FBDIV_RANGE: Range<u16> = 16..320;
 
-        let vco_freq = config.vco_freq;
+        let PLLConfig {
+            vco_freq,
+            refdiv,
+            post_div1,
+            post_div2,
+        } = config;
 
         if !VCO_FREQ_RANGE.contains(&vco_freq) {
             return Err(Error::VcoFreqOutOfRange);
         }
 
-        if !POSTDIV_RANGE.contains(&config.post_div1) || !POSTDIV_RANGE.contains(&config.post_div2)
-        {
+        if !POSTDIV_RANGE.contains(&post_div1) || !POSTDIV_RANGE.contains(&post_div2) {
             return Err(Error::PostDivOutOfRage);
         }
 
@@ -161,7 +165,7 @@ impl<D: PhaseLockedLoopDevice> PhaseLockedLoop<Disabled, D> {
 
         let ref_freq_hz: HertzU32 = xosc_frequency
             .to_Hz()
-            .checked_div(u32::from(config.refdiv))
+            .checked_div(u32::from(refdiv))
             .ok_or(Error::BadArgument)?
             .Hz();
 
@@ -180,11 +184,8 @@ impl<D: PhaseLockedLoopDevice> PhaseLockedLoop<Disabled, D> {
             return Err(Error::FeedbackDivOutOfRange);
         }
 
-        let refdiv = config.refdiv;
-        let post_div1 = config.post_div1;
-        let post_div2 = config.post_div2;
-        let frequency: HertzU32 =
-            (ref_freq_hz * u32::from(fbdiv)) / (u32::from(post_div1) * u32::from(post_div2));
+        let frequency: HertzU32 = ((ref_freq_hz / u32::from(refdiv)) * u32::from(fbdiv))
+            / (u32::from(post_div1) * u32::from(post_div2));
 
         Ok(PhaseLockedLoop {
             state: Disabled {