Contec BX-100n-DC5000-C01 User Manual page 135

7. Appendix
Table 7.5. Function of Each Register < 3 / 4 >
I/O address
03FCH
MCR: Modem Control Register
D7
0
03FDH
LSR: Line Status Regester
D7
0
TEMT THRE
128
Description
D6 D5 D4 D3 D2
0 0 Loop IRQ X
Interrupt control bit
0 : Disable
1 : Enable
Diagnostic local loop-back test
0 : Disable
1 : Enable
D6 D5 D4 D3 D2
BI FE PE
Framing error (1 for occurrence of an error)
Break interrupt (1 for detection of break state)
Transmitter holding register empty
(1 for transmission buffer being empty)
Transmitter empty
(Set to 1 when both transmitter holding register and
transmitter shift register are empty.)
D1 D0
RTS DTR
DTR
0 : Inactive
[HIGH]
1 : Active
[LOW]
RTS 0 : Inactive
[HIGH]
1 : Active
[LOW]
D1 D0
OE DR
Data ready
(1 for existence of received data)
Overrun error
(1 for occurrence of an error)
Parity error (1 for occurrence of an error)
BX-100n User's manual