serial clock kinda sux tbh... put it behind a feature flag

lib/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 [features]
 default = []
 async = []
+clocked-serial = []
 
 [dependencies]
 rand = "0.8.5"

lib/src/processor/memory/mmio/serial.rs

@@ -1,11 +1,12 @@
+use crate::util::get_bit;
+use serde::{Deserialize, Serialize};
 use std::{
     io::{stdout, Write},
     sync::mpsc::{Receiver, Sender},
 };
 
-use serde::{Deserialize, Serialize};
-
-use crate::{constants::CLOCK_SPEED, util::get_bit};
+#[cfg(feature = "clocked-serial")]
+use crate::constants::CLOCK_SPEED;
 
 #[derive(Copy, Clone, Serialize, Deserialize, Debug, PartialEq)]
 enum ClockSource {
@@ -58,6 +59,7 @@ struct InputByte {
 }
 
 const BYTE_DELAY: usize = 2000;
+#[cfg(feature = "clocked-serial")]
 const CLOCK_DIV: usize = CLOCK_SPEED / 8192;
 
 impl InputByte {
@@ -105,6 +107,7 @@ pub struct Serial {
     bits_remaining: u8,
     control: SerialControl,
     target: SerialTarget,
+    #[cfg(feature = "clocked-serial")]
     clock_inc: usize,
 }
 
@@ -115,6 +118,7 @@ pub struct SerialSaveState {
     input_byte: InputByte,
     bits_remaining: u8,
     control: SerialControl,
+    #[cfg(feature = "clocked-serial")]
     clock_inc: usize,
 }
 
@@ -126,6 +130,7 @@ impl SerialSaveState {
             input_byte: serial.input_byte,
             bits_remaining: serial.bits_remaining,
             control: serial.control,
+            #[cfg(feature = "clocked-serial")]
             clock_inc: serial.clock_inc,
         }
     }
@@ -140,6 +145,7 @@ impl Serial {
             bits_remaining: 7,
             control: SerialControl::default(),
             target,
+            #[cfg(feature = "clocked-serial")]
             clock_inc: 0,
         }
     }
@@ -152,6 +158,7 @@ impl Serial {
             bits_remaining: state.bits_remaining,
             control: state.control,
             target,
+            #[cfg(feature = "clocked-serial")]
             clock_inc: state.clock_inc,
         }
     }
@@ -171,9 +178,14 @@ impl Serial {
             &None
         };
         for _ in 0..steps {
+            #[cfg(feature = "clocked-serial")]
+            {
                 self.clock_inc += 1;
-            if self.clock_inc >= CLOCK_DIV {
+                if self.clock_inc < CLOCK_DIV {
+                    continue;
+                }
                 self.clock_inc %= CLOCK_DIV;
+            }
             if ime {
                 self.input_byte.input_delay = self.input_byte.input_delay.saturating_sub(1);
             }
@@ -207,7 +219,6 @@ impl Serial {
                 }
             }
         }
-        }
         will_interrupt
     }