AMD-766AC AMD [Advanced Micro Devices], AMD-766AC Datasheet - Page 40

• Manufacturer Part Number: AMD-766AC
• Description: Peripheral Bus Controller
• Manufacturer: AMD [Advanced Micro Devices]

23167B – March 2001
ASIO. Alternate super IO configuration. 1=Alternate super IO configuration IO ports, 4Eh - 4Fh, are routed to the
LPC bus. 0=These accesses are routed to the ISA bus.
C0A55: LPC Bus Decode Register 4
Configuration space; function 0; offset: 55h. Default: 00h. Read-write.
7:5
Reserved
GP1RANGE. Game port 1 range. Selects one byte of IO address space in the range 200h - 20Fh (where
GP1RANGE specifies the four LSBs of the address) that is routed to the LPC bus.
GP1EN. Game port 1 enable. 1=Game port 1 accesses specified by the GP1RANGE field in this register are routed
to the LPC bus. 0=These accesses are routed to the ISA bus.
C0A56: LPC Bus Decode Register 5
Configuration space; function 0; offset: 56h. Default: 00h. Read-write.
7:5
Reserved
GP2RANGE. Game port 2 range. Selects one byte of IO address space in the range 200h - 20Fh (where
GP2RANGE specifies the four LSBs of the address) that is routed to the LPC bus.
GP2EN. Game port 2 enable. 1=Game port 2 accesses specified by the GP2RANGE field in this register are routed
to the LPC bus. 0=These accesses are routed to the ISA bus.
C0A58: LPC Bus Generic IO Decode Register
Configuration space; function 0; offset: 5B-58h. Default: 0000_DE01h. Read-write.
31:16
Reserved
IOBASE. Generic IO base address. Specifies bits [15:9] of the base address for a 512-byte generic IO address range
that is routed to the LPC bus. This function is disabled if IOBASE is set to 00h.
C0A5C: LPC Bus Generic Memory Decode Register
Configuration space; function 0; offset: 5F-5Ch. Default: 0000_0000h. Read-write.
MEMBASE
MEMBASE. Generic memory base address. Specifies bits [31:20] of the base address for a 1-megabyte generic
memory address range that is routed to the LPC bus. This function is disabled if MEMBASE is set to 000h.
C0A70: Device and Subsystem ID Read-Write Register
Configuration space; function 0; offset: 73-70h. Default: 0000_0000h. Read-write.
31:16
SSID
SSVENDORID and SSID. Subsystem vendor ID and Subsystem ID. The value placed in this register is visible in
C0A2C, C1A2C, C3A2C, and C4A2C.
C0A80/C0A84/C0A88: BIOS Access Control Register
Configuration space; function 0; offset: 8B-80h. Default: 0000_0000h. Read-write. These registers include 24 4-bit
registers called OAR (open at reset) locks. Each 4-bit register applies to a sector of the BIOS in the 5 megabyte
BIOS range at the top of the 4-gigabyte address space as follows:
31:20
C0A84 and C0A80 include 16 four-bit lock registers, OARx where x ranges from 0h to Fh; each four-bit register
controls a 64Kbyte address range at the top megabyte of memory as follows: [FFF(x)_FFFFh: FFF(x)_0000h].
C0A88 includes 8 four-bit lock registers, OARx where x ranges as [E, C, A, 8, 6, 4, 2, 0]; each four-bit register
controls an 8Kbyte address range as follows: [FFBF_(x+1)FFFh: FFBF_(x)000h].
4
GP1EN
4
GP2EN
19:0
Reserved
Preliminary Information
3:0
GP1RANGE
3:0
GP2RANGE
15:0
SSVENDORID
15:9
IOBASE
AMD-766
TM
Peripheral Bus Controller Data Sheet
8:0
Reserved
40