Intel 460GX - Manual (Page 200)

LPC/FWH Interface Configuration
11-10 Intel® 460GX Chipset Software Developer’s Manual
11.1.21 GPIO Base Address (FUNCTION 0)
Address: D0-D3h
Default Value: 00000001h
Attributes: Read/Write
11.1.22 GPIO Enable (FUNCTION 0)
Address: D4h
Default Value 00h
Attributes: Read/Write
11.1.23 LPC COM Decode Ranges (Function 0)
Address: E0h
Default Value: 00h
Attributes: Read/Write
Bit Description
31:16 Reserved.
15:6 Base Address: Provides the 64 bytes of I/O space.
5:1 Reserved.
0 Resource Indicator: Tied to 1 to indicate I/O space
Bit Description
7:1 Reserved.
0 GPIO Enable: When this bit is set to ‘1’, decode of the I/O range pointed to by the GPIO base
register is enabled, and the GPIO Function is enabled.
Bit Description
7 Reserved.
6:4 Decode Range: The following table describes which range to decode for the COMB Port
Bits Decode Range
000 3F8 - 3FF (COM 1)
001 2F8 - 2FF (COM 2)
010 220 - 227
011 228 - 22F
100 238 - 23F
101 2E8 - 2EF (COM 4)
110 338 - 33F
111 3E8 - 3EF (COM 3)