UART Line Status Register
| dr | Data Ready 1 (ready): undefined |
| oe | Overrun Error 1 (error): undefined |
| pe | Parity Error 1 (error): undefined |
| fe | Framing Error 1 (error): undefined |
| bi | Break Interrupt |
| thre | TX Holding Register Empty 1 (empty): undefined |
| temt | Transmitter Empty 1 (empty): undefined |
| fifoerr | RX Data Error in FIFO 1 (error): undefined |