From c9271834b5f2794dbdd44c72635ee9d5dccc5b0f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=A3o=20Magalh=C3=A3es?= <joamag@gmail.com>
Date: Thu, 27 Apr 2023 15:08:47 +0100
Subject: [PATCH] feat: made receive a delayed operation This changes the way
the device is called.
---
src/serial.rs | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/src/serial.rs b/src/serial.rs
index 4578c103..507a964b 100644
--- a/src/serial.rs
+++ b/src/serial.rs
@@ -22,6 +22,7 @@ pub struct Serial {
timer: i16,
length: u16,
bit_count: u8,
+ byte_send: u8,
byte_receive: u8,
int_serial: bool,
device: Box<dyn SerialDevice>,
@@ -38,6 +39,7 @@ impl Serial {
timer: 0,
length: 512,
bit_count: 0,
+ byte_send: 0x0,
byte_receive: 0x0,
int_serial: false,
device: Box::<NullDevice>::default(),
@@ -53,6 +55,7 @@ impl Serial {
self.timer = 0;
self.length = 512;
self.bit_count = 0;
+ self.byte_send = 0x0;
self.byte_receive = 0x0;
self.int_serial = false;
}
@@ -120,8 +123,10 @@ impl Serial {
// executes the send and receive operation immediately
// this is considered an operational optimization with
// no real effect on the emulation (ex: no timing issues)
+ // then stores the byte to be sent to the device so that
+ // it's sent by the end of the send cycle
self.byte_receive = self.device.send();
- self.device.receive(self.data);
+ self.byte_send = self.data;
}
}
_ => warnln!("Writing to unknown Serial location 0x{:04x}", addr),
@@ -173,6 +178,10 @@ impl Serial {
self.length = 0;
self.bit_count = 0;
+ // received the byte on the device as the
+ // complete send operation has been performed
+ self.device.receive(self.byte_send);
+
// signals the interrupt for the serial
// transfer completion, indicating that
// a new byte is ready to be read
--
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