Digi NS7520 manual Dcd, Current data carrier detect state, Current ring indicator state

S e r i a l C h a n n e l r e g i s t e r s

Bits	Access	Mnemonic	Reset	Description
D21:20	R	RXFDB	0	Receive FIFO data available
				00	Full-word
				01	One byte
				10	Half-word
				11 Three bytes (LENDIAN determines which
					three)
				Identifies the number of valid bytes contained
				in the next long word to be read from the Serial
				Channel FIFO Data register. The next read of
				the FIFO can contain one, two, three, or four
				valid bytes of data. This field must be read
				before the FIFO is read, to determine which
				bytes of the 4-byte long word contain valid
				data.
				Normal Endian byte-ordering rules apply to the
				Serial Channel FIFO Data register.
D19	R	DCD	0	Current data carrier detect state
				0	Inactive
				1	Active
				Identifies the current state of the EIA data
				carrier detect signal.
D18	R	RI	0	Current ring indicator state
				0	Inactive
				1	Active
				Indicates the current state of the EIA ring
				indicator signal.
D17	R	DSR	0	Current data set ready state
				0	Inactive
				1	Active
				Indicate the current state if the EIA data set
				ready signal.
D16	R	CTS	0	Current clear to send state
				0	Inactive
				1	Active
				Identifies the current state of the EIA clear to
				send signal.

Table 89: Serial Channel Status Register A bit definition

2 3 8 N S 7 5 2 0 H a r d w a r e R e f e r e n c e , R e v . D 0 3 / 2 0 0 6