290 AMD Geodeā„¢ SC2200 Processor Data Book
Core Logic Module - X-Bus Expansion Interface - Function 5
32580B

6.4.5.1 X-Bus Expansion Support Registers

F5 Index 10h, Base Address Register 0 (F5BAR0) set the

base address that allows PCI access to additional I/O Con-

trol support registers. Table 6-40 shows the support regis-

ters accessed through F5BAR0.

Index 59h-5Fh Reserved Reset Value: xxh
Index 60h-63h Scratchpad: Usually used for Device Number (R/W) Reset Value: 00000000h
BIOS writes a value, of the Device number. Expected value: 00002200h.
Index 64h-67h Scratchpad: Usually used for Configuration Block Address (R/W) Reset Value: 00000000h
BIOS writes a value, of the Configuration Block Address.
Index 68h-FFh Reserved
Table 6-39. F5: PCI Header Registers for X-Bus Expansion (Continued)
Bit Description
Table 6-40. F5BAR0+I/O Offset: X-Bus Expansion Registers
Bit Description
Offset 00h-03h I/O Control Register 1 (R/W) Reset Value: 010C0007h
31:28 Reserved.
27 IO_ENABLE_SIO_IR (Enable Integrated SIO Infrared).
0: Disable.
1: Enable.
26:25 IO_SIOCFG_IN (Integrated SIO Input Configuration). These two bits can be used to disable the integrated SIO totally or
limit/control the base address.
00: Integrated SIO disable.
01: Integrated SIO configuration access disable.
10: Integrated SIO base address 02Eh/02Fh enable.
11: Integrated SIO base address 015Ch/015Dh enable.
24 IO_ENABLE_SIO_DRIVING_ISA_BUS (Enable Integrated SIO ISA Bus Control). Allow the integrated SIO to drive the
internal ISA bus.
0: Disable.
1: Enable. (Default)
23:21 Reserved. Set to 0.
20 IO_USB_SMI_PWM_EN (USB Internal SMI). Route USB-generated SMI to SMI Status Register in F1BAR0+I/O Offset
00h/02h[14].
0: Disable.
1: Enable.
19 IO_USB_SMI_EN (USB SMI Configuration). Allow USB-generated SMIs.
0: Disable.
1: Enable.
If bits 19 and 20 are enabled, the SMI generated by the USB is reported via the Top Level SMI status register at F1BAR0+I/
O Offset 00h/02h[14].
If only bit 19 is enabled, the USB can generate an SMI but there is no status reporting.
18 IO_USB_PCI_EN (USB). Enables USB ports.
0: Disable.
1: Enable.
17:0 Reserved.