AMD-761 Datasheet, PDF (87/264 Pages) Advanced Micro Devices – AMD-761-TM System Controller Software/BIOS Design Guide

24081D—February 2002
Preliminary Information
AMD-761™ System Controller Software/BIOS Design Guide
Bit Definitions
Bit Name
31–29 AGP_Clk_Mux
28–26 Sys_Clk_Mux
25 Type_Det
24 S2K_Thresh
23 K7_PP_En
22 IG_PP_En
21–20 Clk_Speed
19–18 Reserved
17–16 S2K0_Bus_Len
15 Tristate_En
14 NAND_En
Config Status (Dev0:F0:0x88)
Function
AGP Clock Mux
For internal test only.
System Clock Mux
For internal test only.
Type Detect
0 = This installed card in the AGP slot uses 1.5-V signalling.
1 = This installed card in the AGP slot uses 3.3-V signalling.
AMD Athlon™ Processor System Bus Threshold
AMD Athlon™ processor system bus threshold range select for AMD Athlon™ system bus
I/O cells. When Low, these AMD Athlon processor system bus inputs sense input
thresholds between 1.35 V and 1.9 V. When High, the inputs sense thresholds between 2.0
V and 2.2 V.
AMD Athlon Processor Push-Pull Driver Enable
When set, this bit indicates that the AMD Athlon processor push-pull drivers are enabled.
AMD-761™ System Controller Push-Pull Driver Enable
When set, this bit indicates that the AMD-761 system controller push-pull drivers are
enabled.
Clock Speed
This bit field defines the speed of the system clock received by the AMD-761 system
controller:
00 = 100 MHz
01 = 66 MHz
10 = Reserved
11 = 133 MHz
Reserved
AMD Athlon Processor System Bus Length
This bit field indicates the relative length of the AMD Athlon processor system bus trace
routing on the motherboard.
00 = Short
01..............
10...............
1 = Long
Tristate Enable
For internal test only.
NAND Enable
For internal test only.
Chapter 2
AMD-761™ System Controller Programmer’s Interface
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