Changeset e5dd493 in avrstuff for libs

Timestamp:

Sep 8, 2019, 9:09:42 AM (5 years ago)

Author:

Adrien Destugues <pulkomandy@…>

Branches:

main

Children:

c956fd4

Parents:

6f22754

Message:

usart: some cleanups.

Location:

libs/usart

Files:

• usart.c (modified) (3 diffs)
• usart.h (modified) (1 diff)

libs/usart/usart.c

@@ -8 +8 @@
 #endif
 
-#ifdef __AVR_ATmega128__
 // FIXME there are two USARTs in this case and we should be able to drive either
-#define UBRRH UBRR0H
-#define UBRRL UBRR0L
-#define UCSRA UCSR0A
-#define UCSRC UCSR0C
-#define UCSRB UCSR0B
-#define UDR   UDR0
+
+// Compatibility for devices with single USART only
+#ifdef __AVR_ATmega8__
+#define UBRR0H UBRRH
+#define UBRR0L UBRRL
+#define UCSR0A UCSRA
+#define UCSR0C UCSRC
+#define UCSR0B UCSRB
+#define UDR0   UDR
+#define UDRE0  UDRE
+#define RXC0   RXC
 #endif
 
-//This function is used to initialize the USART
 void USARTInit()
 {
@@ -51 +54 @@
 
 
-//This fuction writes the given "data" to
-//the USART which then transmit it via TX line
 void USARTWriteChar(char data)
 {
@@ -67 +68 @@
 
 
-//This function is used to read the available data
-//from USART. This function will wait untill data is
-//available.
 char USARTReadChar()
 {

libs/usart/usart.h

@@ -1 +1 @@
 /* USART i/o library
- * Copyright 2010-2014, Adrien Destugues <pulkomandy@pulkomandy.tk>
+ * Copyright 2010-2019, Adrien Destugues <pulkomandy@pulkomandy.tk>
  * Distributed under the terms of the MIT Licence */
 
-#include <stdint.h>
+/** Initialize the USART.
+ *
+ * Baudrate is set according to the BAUD define.
+ * Currently the USART is set to 8N1, except on ATmega128 where it's set to 7E1
+ * (don't ask why, I don't remember). This should be made configurable.
+ *
+ * On ATmega128, this always uses the first USART.
+ */
+void USARTInit();
 
-void USARTInit();
+/** Write a byte to the USART.
+ *
+ * This function blocks if the USART is not ready to accept any data. There is
+ * no IO buffering.
+ */
 void USARTWriteChar(char data);
+
+/** Write an 8bit integer as hex to the USART.
+ */
 void USARTWriteHex(unsigned char i);
+
+/** This function is used to read the available data from USART.
+ *
+ * It waits untill data is available.
+ */
+char USARTReadChar();