
VT8231
Preliminary Revision 0.8
October 29, 1999
-
48-
Register Descriptions - Super-I/O I/O Ports
7HFKQRORJLHV,QF
:H &RQQHFW
Index EE
–
Serial Port Configuration ............................. RW
7
Serial Port 2 High Speed Enable
0
Disable ...................................................default
1
Enable
6
Serial Port 1 High Speed Enable
0
Disable ...................................................default
1
Enable
5-3
Serial Port 2 Mode
000 Standard
001 IrDA (HIPSIR)
010 Amplitude shift keyed IR @ 500KHz
011 -reserved-
1xx -reserved-
2
Serial Port 2 Half Duplex
0
Disable ...................................................default
1
Enable
1
Serial Port 2 TX Output Inversion
0
Disable ...................................................default
1
Enable
0
Serial Port 2 RX Input Inversion
0
Disable ...................................................default
1
Enable
Index EF
–
Power Down Control .................................... RW
7-6
Reserved
........................................ always reads 0
5
Clock Power Down
0
Normal operation ...................................default
1
Power Down
4
Parallel Port Power Down
0
Normal operation ...................................default
1
Power Down
3
Serial Port 2 Power Down
0
Normal operation ...................................default
1
Power Down
2
Serial Port 1 Power Down
0
Normal operation ...................................default
1
Power Down
1
FDC Power Down
0
Normal operation ...................................default
1
Power Down
0
All Power Down
0
Normal operation ...................................default
1
Power Down All
Index F0
–
Parallel Port Control ..................................... RW
7
PS2 Type BiDirectionl Parallel Port
0
Disable...................................................default
1
Enable
6
EPP Direction by Register not by IOW
0
Disable...................................................default
1
Enable
5
EPP+ECP
0
Disable...................................................default
1
Enable
4
EPP Version
0
Version 1.9 ............................................default
1
Version 1.7
3-0
Reserved
........................................always reads 0
Index F1
–
Serial Port Control ........................................ RW
7-6
Reserved
........................................always reads 0
5
IR Loop Back
0
Disable...................................................default
1
Enable
4
Serial Port 2 Power-Down State
0
Normal...................................................default
1
Tristate output in power down mode
3
Serial Port 1 Power-Down State
0
Normal...................................................default
1
Tristate output in power down mode
2
IR Dedicated Pin (IRTX/IRRX) Select
0
IRTX / IRRX Output from Serial Port 2......def
1
Function 0 Rx76[5] = 0:
IRRX output from dedicated pin D12
IRTX output from dedicated pin E12
1-0
Reserved
........................................always reads 0
Index F2
–
Test Mode (Do Not Program) ....................... RW
Index F4
–
Test Mode (Do Not Program) ....................... RW