update comments
This commit is contained in:
@@ -64,17 +64,17 @@
|
||||
// Table 20-1 : Baud Rate Calculation
|
||||
#define USART_BAUDRATE 115200
|
||||
#define BAUD_PRESCALER (DIV_ROUND_CLOSEST(F_CPU, (16 * USART_BAUDRATE)) - 1)
|
||||
// Table 20-8 : Mode Selection
|
||||
// Table 20-8 : Mode Selection (USART Mode SELect)
|
||||
#define ASYNCHRONOUS (0<<UMSEL01 | 0<<UMSEL00)
|
||||
#define SYNCHRONOUS (0<<UMSEL01 | 1<<UMSEL00)
|
||||
// Table 20-9 : Parity Bit Selection
|
||||
// Table 20-9 : Parity Bit Selection (USART Parity Mode)
|
||||
#define PARITY_DISABLED (0<<UPM01 | 0<<UPM00)
|
||||
#define PARITY_EVEN (1<<UPM01 | 0<<UPM00)
|
||||
#define PARITY_ODD (1<<UPM01 | 1<<UPM00)
|
||||
// Table 20-10 : Stop Bit Selection
|
||||
// Table 20-10 : Stop Bit Selection (USART Stop Bit Select)
|
||||
#define STOP_ONE_BIT (0<<USBS0)
|
||||
#define STOP_TWO_BIT (1<<USBS0)
|
||||
// Table 20-11 : Data Bit Selection
|
||||
// Table 20-11 : Data Bit Selection (USART Character SiZe)
|
||||
#define DATA_FIVE_BIT (0<<UCSZ02 | 0<<UCSZ01 | 0<<UCSZ00)
|
||||
#define DATA_SIX_BIT (0<<UCSZ02 | 0<<UCSZ01 | 1<<UCSZ00)
|
||||
#define DATA_SEVEN_BIT (0<<UCSZ02 | 1<<UCSZ01 | 0<<UCSZ00)
|
||||
@@ -100,8 +100,8 @@ void uart_init() {
|
||||
}
|
||||
|
||||
void uart_tx(char c) {
|
||||
while (TEST(UCSR0A, UDRE0) == 0); // 20.11.2 : do nothing until UDR emission buffer is empty, if UDREn flag is 1, UCSRnA register is empty
|
||||
UDR0 = c; // 20.11.1 : Put data into buffer, UDRn – USART I/O Data Register (read and write)
|
||||
while (TEST(UCSR0A, UDRE0) == 0); // 20.11.2 : do nothing until UDR emission buffer is empty, if UDREn flag is 1, UCSRnA register is empty
|
||||
UDR0 = c; // 20.11.1 : Put data into buffer, UDRn – USART I/O Data Register (read and write)
|
||||
}
|
||||
|
||||
int main() {
|
||||
|
||||
Reference in New Issue
Block a user