Multi-Tech Systems MT5600SMI-L92, MT5600SMI-92 Parallel Interface Registers, Register BIT No Name

Chapter 4 – SocketModem Parallel Interface – A Programmer's Description

Table 4–1. Parallel Interface Registers

Register	Register				BIT No.
No.	Name	7	6	5	4	3	2	1	0
7	Scratch Register (SCR)				Scratch Register
6	Modem Status Register	Data	Ring	Data Set	Clear to	Delta Data	Trailing	Delta Data	Delta Clear
	(MSR)	Carrier	Indicator	Ready	Send CTS)	Carrier	Edge of Ring	Set Ready	to Send
		Detect	(RI)	(DSR)		Detect	Indicator	(DDSR)	(DCTS)
		(DCD)				(DDCD)	(TERI)
5	Line Status Register	RX	Transmitter	Transmitter	Break	Framing	Parity	Overrun	Receiver
	(LSR)	FIFO	Empty	Buffer	Interrupt	Error	Error	Error	Data
		Error	(TEMT)	Register	(BI)	(FE)	(PE)	(OE)	Ready
				Empty					(DR)
				(THRE)
4	Modem Control	0	0	0	Local	Out 2	Out 1	Request	Data
	Register (MCR)				Loopback			to Send	Terminal
								(RTS)	Ready
									(DTR)
3	Line Control Register	Divisor	Set	Stick	Even	Parity	Number	Word	Word Length
	(LCR)	Latch	Break	Parity	Parity	Enable	of Stop	Length	Select
		Access Bit			Select	(PEN)	Bits	Select	Bit 0
		(DLAB)			(EPS)		(STB)	Bit 1	(WLSO)
								(WLS1)
2	Interrupt Identify	FIFOs	FIFOs	0	0	Pending	Pending	Pending	“0” if
	Register (IIR)	Enabled	Enabled			Interrupt ID	Interrupt ID	Interrupt ID	Interrupt
	(Read Only)					Bit 2	Bit 1	Bit 0	Pending
2	FIFO Control Register	Receiver	Receiver	Reserved	Reserved	DMA	TX FIFO	RX FIFO	FIFO
	(FCR)	Trigger	Trigger			Mode	Reset	Reset	Enable
	(Write Only)	MSB	LSB			Select
1	Interrupt Enable	0	0	0	0	Enable	Enable	Enable	Enable
(DLAB = 0)	Register (ER)					Modem	Receiver	Transmitter	Received
						Status	Line Status	Holding	Data
						Interrupt	Interrupt	Register	Available
						(EDSSI)	(ELSI)	Empty	Interrupt
								Interrupt	(ERBFI)
								(ETBEI)
0	Transmitter Buffer			Transmitter	FIFO Buffer Register (Write Only)
(DLAB = 0)	Register
	(THR)
0	Receiver Buffer			Receiver FIFO Buffer Register (Read Only)
(DLAB = 0)	Register (RBR)
1	Divisor Latch MSB				Divisor Latch MSB
(DLAB = 1)	Register (DLM)
0	Divisor Latch LSB				Divisor Latch LSB
(DLAB = 1)	Register (DLL)

Multi-Tech Systems, Inc. SocketModem MT5600SMI Developer’s Guide 19