mcxa/crc: document the use of align_to

2 files changed, 23 insertions, 7 deletions

diff --git a/embassy-mcxa/src/crc.rs b/embassy-mcxa/src/crc.rs
index 83b5eca8d..f01a671c4 100644
--- a/embassy-mcxa/src/crc.rs
+++ b/embassy-mcxa/src/crc.rs
@@ -222,7 +222,15 @@ impl<'d> Crc<'d, Crc16> {
     }
 
     /// Feeds a slice of bytes into the CRC peripheral. Returns the computed checksum.
-    pub fn feed_bytes(&mut self, bytes: &[u8]) -> u16 {
+    ///
+    /// The input is split using [`align_to::<u32>`] into:
+    /// - `prefix`: unaligned leading bytes,
+    /// - `data`: aligned `u32` words,
+    /// - `suffix`: trailing bytes.
+    ///
+    /// This allows efficient 32‑bit writes where possible, falling back to byte writes
+    /// for the remainder.
+    pub fn feed(&mut self, bytes: &[u8]) -> u16 {
         let (prefix, data, suffix) = unsafe { bytes.align_to::<u32>() };
 
         for b in prefix {
@@ -325,7 +333,15 @@ impl<'d> Crc<'d, Crc32> {
     }
 
     /// Feeds a slice of bytes into the CRC peripheral. Returns the computed checksum.
-    pub fn feed_bytes(&mut self, bytes: &[u8]) -> u32 {
+    ///
+    /// The input is split using [`align_to::<u32>`] into:
+    /// - `prefix`: unaligned leading bytes,
+    /// - `data`: aligned `u32` words,
+    /// - `suffix`: trailing bytes.
+    ///
+    /// This allows efficient 32‑bit writes where possible, falling back to byte writes
+    /// for the remainder.
+    pub fn feed(&mut self, bytes: &[u8]) -> u32 {
         let (prefix, data, suffix) = unsafe { bytes.align_to::<u32>() };
 
         for b in prefix {
diff --git a/examples/mcxa/src/bin/crc.rs b/examples/mcxa/src/bin/crc.rs
index 417b4f865..f963620cc 100644
--- a/examples/mcxa/src/bin/crc.rs
+++ b/examples/mcxa/src/bin/crc.rs
@@ -16,23 +16,23 @@ async fn main(_spawner: Spawner) {
     let buf = b"123456789";
 
     let mut crc = Crc::new_ccitt_false(p.CRC0.reborrow());
-    let sum = crc.feed_bytes(buf);
+    let sum = crc.feed(buf);
     assert_eq!(sum, 0x29b1);
 
     let mut crc = Crc::new_maxim(p.CRC0.reborrow());
-    let sum = crc.feed_bytes(buf);
+    let sum = crc.feed(buf);
     assert_eq!(sum, 0x44c2);
 
     let mut crc = Crc::new_kermit(p.CRC0.reborrow());
-    let sum = crc.feed_bytes(buf);
+    let sum = crc.feed(buf);
     assert_eq!(sum, 0x2189);
 
     let mut crc = Crc::new_iso_hdlc(p.CRC0.reborrow());
-    let sum = crc.feed_bytes(buf);
+    let sum = crc.feed(buf);
     assert_eq!(sum, 0xcbf4_3926);
 
     let mut crc = Crc::new_posix(p.CRC0.reborrow());
-    let sum = crc.feed_bytes(buf);
+    let sum = crc.feed(buf);
     assert_eq!(sum, 0x765e_7680);
 
     defmt::info!("CRC successful");