Analog Devices ADSP-SC58 Series Hardware Reference Manual page 815

ADSP-SC58x UART Register Descriptions
Table 17-11: UART_CTL Register Fields (Continued)
Bit No.
(Access)
26 XOFF
(R/W)
25 MRTS
(R/W)
24 TPOLC
(R/W)
23 RPOLC
(R/W)
17–28
Bit Name
Transmitter off.
The UART_CTL.XOFF bit (if set) turns off transmission (XOFF) by preventing the
content of THR from being continued to TSR. When set, this bit turns on transmis-
sion (XON). The state of the UART_CTL.XOFF bit is ignored if the
UART_CTL.ACTS bit is set.
Manual Request to Send.
The UART_CTL.MRTS bit controls the state of the UART_RTS output pin when the
UART_CTL.ARTS bit is cleared. When UART_CTL.MRTS is cleared, the UART
deasserts the UART_RTS pin, signaling to the external device that the UART is not
ready to receive. When UART_CTL.MRTS is set, the UART asserts the UART_RTS
pin, signaling to the external device that the UART is ready to receive.
IrDA TX Polarity Change.
The UART_CTL.TPOLC bit selects the active low or high polarity for IrDA commu-
nications. This bit is effective only in IrDA mode. If set, in IrDA mode, the UART_TX
pin idles high. In UART or MDB mode, it is inverted-NRZ. If cleared, in IrDA mode,
the UART_TX pin idles low. In UART or MDB mode, it is NRZ.
IrDA RX Polarity Change.
The UART_CTL.RPOLC bit selects the active low or high polarity for IrDA commu-
nications. This bit is effective only in IrDA mode. If set, in IrDA mode, the UART_RX
pin idles high. In UART or MDB mode, it is inverted-NRZ. If cleared, in IrDA mode,
the UART_RX pin idles low. In UART or MDB mode, it is NRZ.
ADSP-SC58x/ADSP-2158x SHARC+ Processor Hardware Reference
Description/Enumeration
0 Transmission ON, if ACTS=0
1 Transmission OFF, if ACTS=0
0 Deassert RTS pin when ARTS=0
1 Assert RTS pin when ARTS=0
0 Active-low TX polarity setting
1 Active-high TX polarity setting
0 Active-low RX polarity setting
1 Active-high RX polarity setting