串口通信

if (TI0 == 1) // Check if transmit flag is set

{

TI0 = 0; // Clear interrupt flag

if (UART_Buffer_Size != 1) // If buffer not empty

{

// If a new word is being output

if ( UART_Buffer_Size == UART_Input_First )

{

UART_Output_First = 0;

}

Byte = UART_Buffer[UART_Output_First]; // Store a character in the variable byte

if ((Byte >= 0x61) && (Byte <= 0x7A)) // If upper case letter

{

Byte -= 32;

}

SBUF0 = Byte; // Transmit to Hyperterminal

UART_Output_First++; // Update counter

UART_Buffer_Size--; // Decrease array size

}

else

{

UART_Buffer_Size = 0; // Set the array size to 0

TX_Ready = 1; // Indicate transmission complete

}

}

}