OWL_UART_CTL
owl_uart_write(port, ctl, OWL_UART_CTL);
ctl = owl_uart_read(port, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
val = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
ctl = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, ctl, OWL_UART_CTL);
old_ctl = owl_uart_read(port, OWL_UART_CTL);
owl_uart_write(port, val, OWL_UART_CTL);
owl_uart_write(port, old_ctl, OWL_UART_CTL);
ctl = owl_uart_read(port, OWL_UART_CTL);