ASIX AX99100 - Serial Interface for COM Port; Com Port Pin Description

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Copyright © 2016 ASIX Electronics Corporation. All rights reserved.
AX99100
PCIe to Multi I/O Controller
1.4.2 Serial Interface for COM Port
Table 1-5: Serial Interface for COM Port Pin Description
Serial Interface for COM Port
Pin Name
Type
Pin No
Pin Description
TXD1
TXD2
TXD3
TXD4
O5/4m
9
68
50
42
Transmit data output to transceiver or IrDA data output to IR LED
DTR1
DTR2
DTR3
DTR4
B5/PD/4m
8
67
49
41
Data Terminal Ready
These pins have internal pull-down during reset. If there is the external pull-up
resisters connected to these pins separately, it will work for RS-232 function with
active low. Otherwise, it will work for RS-485 function (DXEN) with active high
and the output can be enabled by register (the default is disabled). Please
reference to Section 3.2.
RTS1
RTS2
RTS3
RTS4
O5/4m
7
66
48
40
Request to send (Active Low)
Note: These pins will be changed to RXEN when Software enabled RS-485
function for the corresponding ports.
RXD1
RXD2
RXD3
RXD4
I5/PU
5
65
47
38
Serial received data input from transceiver or IrDA data input from IrDA
detector.
RI1
RI2
RI3
RI4
I5
3
64
46
34
Ring Indicator (Active Low)
DSR1
DSR2
DSR3
DSR4
I5
4
63
45
33
Data Set Ready (Active Low)
DCD1
DCD2
DCD3
DCD4
I5
2
62
44
32
Data Carrier Detect (Active Low)
CTS1
CTS2
CTS3
CTS4
I5
1
61
43
31
Clear to send (Active Low)
Note 1: Serial Port 1 and 2 are only valid when CHIP_MODE = 001, 011, 101 and 110.
Note 2: Serial Port 3 and 4 are only valid when CHIP_MODE = 011.