- old_dll = serial_in(p, UART_DLL);
- old_dlm = serial_in(p, UART_DLM);
-
- serial_out(p, UART_DLL, 0);
- serial_out(p, UART_DLM, 0);
-
- id = serial_in(p, UART_DLL) | serial_in(p, UART_DLM) << 8;
-
- serial_out(p, UART_DLL, old_dll);
- serial_out(p, UART_DLM, old_dlm);