Intel BFCBASE Data Sheet - Page 127

FSB: Front Side Bus Speed, Example

Page 127 highlights

Features 7.4.3.3.2 Offset: 16h-19h Bit 31:30 29:21 Reserved 00b-11b: Reserved Extended Family 00h-0Fh: Extended Family 21:18 Extended Model 17:16 15:14 0h-Fh: Extended Model Reserved 00b-11b: Reserved Processor Type 00b-11b: Processor Type 13:10 Processor Family 0h-Fh: Processor Family 9:6 Processor Model 0h-Fh: Processor Model 5:2 Processor Stepping 0h-Fh: Processor Stepping 1:0 Reserved 00b-11b: Reserved Description FSB: Front Side Bus Speed This location contains the front side bus frequency information. Systems may need to read this offset to decide if all installed processors support the same front side bus speed. Because the FSB is described as a 4X data bus, the frequency given in this field is 1066 MTS. The data provided is the speed, rounded to a whole number, and reflected in hex. Writes to this register have no effect. Example: The Intel® Xeon® Processor 7200 Series and 7300 Series supports a 1066 MTS front side bus. Therefore, offset 1A - 1Bh has a value of 042Ah. Offset: 1Ah-1Bh Bit 15:0 Front Side Bus Speed 0000h-FFFFh: MHz Description Document Number: 318080-002 127

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142

Document Number: 318080-002
127
Features
7.4.3.3.2
FSB: Front Side Bus Speed
This location contains the front side bus frequency information. Systems may need to
read this offset to decide if all installed processors support the same front side bus
speed. Because the FSB is described as a 4X data bus, the frequency given in this field
is 1066 MTS. The data provided is the speed, rounded to a whole number, and reflected
in hex. Writes to this register have no effect.
Example
: The Intel
®
Xeon
®
Processor 7200 Series and 7300 Series supports a 1066
MTS front side bus. Therefore, offset 1A - 1Bh has a value of 042Ah.
Offset:
16h-19h
Bit
Description
31:30
Reserved
00b-11b: Reserved
29:21
Extended Family
00h-0Fh: Extended Family
21:18
Extended Model
0h-Fh: Extended Model
17:16
Reserved
00b-11b: Reserved
15:14
Processor Type
00b-11b: Processor Type
13:10
Processor Family
0h-Fh: Processor Family
9:6
Processor Model
0h-Fh: Processor Model
5:2
Processor Stepping
0h-Fh: Processor Stepping
1:0
Reserved
00b-11b: Reserved
Offset:
1Ah-1Bh
Bit
Description
15:0
Front Side Bus Speed
0000h-FFFFh: MHz