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G
SuperI/O Module
(Continued)
4.4.2.4
Serial Ports 1 and 2 are identical, except for their reset val-
ues.
LDN 03h and 08h - Serial Ports 1 and 2
Serial Port 1 is designated as LDN 03h and Serial Port 2 as
LDN 08h. Table 4-11 lists the configuration registers which
affect Serial Ports 1 and 2. Only the last register (F0h) is
described here (Table 4-12). See Table 4-3 "Standard Con-
figuration Registers" on page 104 for descriptions of the
others.
Table 4-11. Relevant Serial Ports 1 and 2 Registers
Index
Type
Configuration Register or Action
Reset Value
Port 1
Port 2
30h
R/W
Activate.
See also bit 0 of the SIOCF1 register.
00h
00h
60h
R/W
Base Address MSB register.
Bits [7:3] (for A[15:11]) are RO, 00000b.
03h
02h
61h
R/W
Base Address LSB register
. Bit [2:0] (for A[2:0]) are RO, 000b.
F8h
F8h
70h
R/W
Interrupt Number.
04h
03h
71h
R/W
Interrupt Type.
Bit 1 is R/W; other bits are RO.
03h
03h
74h
RO
Report no DMA assignment
.
04h
04h
75h
RO
Report no DMA assignment.
04h
04h
F0h
R/W
Serial Ports 1 and 2 Configuration register.
02h
02h
Table 4-12. Serial Ports 1 and 2 Configuration Register
Bit
Description
Index F0h
Serial Ports 1 and 2 Configuration Register (R/W)
Reset Value: 02h
7
Bank Select Enable
. Enables bank switching for Serial Ports 1 and 2.
0: Disabled. (Default)
1: Enabled.
Reserved.
Busy Indicator. (RO)
This bit can be used by power management software to decide when to power-down Serial Ports 1
and 2 logical devices.
0: No transfer in progress. (Default)
1: Transfer in progress.
Power Mode Control.
When the logical device is active in:
0: Low power mode - Serial Ports 1 and 2 Clock disabled. The output signals are set to their default states. Registers are
maintained. (Unlike Active bit in Index 30h that also prevents access to Serial Ports 1 or 2 registers.)
1: Normal power mode - Serial Ports 1 and 2 clock enabled. Serial Ports 1 and 2 are functional when the respective logical
devices are active. (Default)
TRI-STATE Control
. This bit controls the TRI-STATE status of the device output pins when it is inactive (disabled).
0: Disabled. (Default)
1: Enabled when device inactive.
6:3
2
1
0