r6781-12 Conexant Systems, Inc., r6781-12 Datasheet - Page 18

• Manufacturer Part Number: r6781-12
• Description: Embedded Modem Family
• Manufacturer: Conexant Systems, Inc.

Table 2-1. Parallel Interface Registers (1 of 2)
2-4
Register
DLAB = 0
DLAB = 0
DLAB = 0
Number
7
6
5
4
3
2
1
0
0
Scratch
Register
(SCR)
Modem
Status
Register
(MSR)
Line Status
Register
(LSR)
Modem
Control
Register
(MCR)
Line
Control
Register
(LCR)
Interrupt
Identify
Register
(IIR) (Read
Only)
Interrupt
Enable
Register
(IER)
Transmitter
Holding
Register
(THR)
Receiver
Buffer
Register
(RBR)
Register
Name
Data
Carrier
Detect
(DCD)
Divisor
Latch
Access Bit
(DLAB)
7
0
0
0
0
The parallel interface registers are identified in
Ring
Indicator
(RI)
Transmitter
Empty
(TEMT)
Set Break
(SB)
6
0
0
0
Data Set
Ready
(DSR)
Transmitter
Holding
Register
(THRE)
Stick Parity
(SP)
Transmitter Holding Register (Write Only)
5
0
0
0
Conexant
Receiver Buffer Register (Read Only)
Clear to
Send (CTS)
Break
Interrupt
(BI)
Local
Loopback
Even Parity
Select
(EPS)
Scratch Register
4
0
0
Bit Number
Delta Data
Carrier
Detect
(DDCD)
Framing
Error (FE)
Parity
Enable
(PEN)
Enable
Modem
Status
Interrupt
(EDSSI)
Out 2
3
0
Table
Trailing
Edge of
Ring
Indicator
(TERI)
Parity Error
(PE)
Number of
Stop Bits
(STB)
Pending
Interrupt ID
Bit 1
(PL1)
Enable
Receiver
Line Status
Interrupt
(ELSI)
Out 1
2
2-1.
EmbeddedModem Family
Delta Data
Set Ready
(DDSR)
Overrun
Error (OE)
Request to
Send (RTS)
Word
Length
Select Bit 1
(WLS1)
Pending
Interrupt ID
Bit 0
(PL0)
Enable
Transmitter
Holding
Register
Empty
Interrupt
(ETBEI)
1
D224ATLVDSC
Delta Clear
to Send
(DCTS)
Data Ready
(DR)
Data
Terminal
Ready
(DTR)
Word
Length
Select Bit 0
(WLS0)
0 if
Interrupt
Pending
(IP)
Enable
Received
Data
Available
Interrupt
(ERBFI)
0