Lenovo NetVista A40p Hardware Maintenance Manual (HMM) for NetVista 2271, 6840 - Page 139

ROM and RAM Addresses, Always eliminate conflicts in these areas before replacing any

Get Lenovo NetVista A40p PDF manuals and user guides View all Lenovo NetVista A40p manuals
Add to My Manuals
Save this manual to your list of manuals

Page 139 highlights

ROM and RAM Addresses Adapter cards with processors can contain RAM and ROM. If the adapter cards have onboard memory, then the following are true. v ROM contains operating instructions for the adapter I/O. v RAM is used for buffering. Two adapters using the same memory area will cause a failure. This failure might appear as a hardware failure. The IRQ levels, DMA channels, I/O address, and ROM and RAM addresses all become potential conflicts and system problems. When conflicts arise, they might show up as system hangs, lost or missing devices, incorrect or bad data, or failing diagnostics. Always eliminate conflicts in these areas before replacing any hardware components. Chapter 10. Related Service Information 133

  • 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
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
ROM and RAM Addresses
Adapter cards with processors can contain RAM and ROM. If the adapter cards
have onboard memory, then the following are true.
v
ROM contains operating instructions for the adapter I/O.
v
RAM is used for buffering.
Two adapters using the same memory area will cause a failure.
This failure might
appear as a hardware failure.
The IRQ levels, DMA channels, I/O address, and ROM and RAM addresses all
become potential conflicts and system problems. When conflicts arise, they might
show up as system hangs, lost or missing devices, incorrect or bad data, or failing
diagnostics.
Always eliminate conflicts in these areas before replacing any
hardware components.
Chapter 10. Related Service Information
133