发明名称 |
ADD-IN BOARD WITH ENABLE/DISABLE EXPANSION ROM FOR PCI BUS COMPUTERS |
摘要 |
An adapter or add-in card for using in a peripheral component interconnect (PCI) computer includes a universal module which couples the card to the PCI bus. The module includes a set of selectively programmable configuration registers which are loaded by a microprocessor on the adapter. A circuit arrangement on the module issues a command which inhibits the PCI processor from accessing the configuration registers until fully loaded. Another circuit arrangement presents the Expansion ROM base address register as a "read/write" register or a read only register with all bits set to logical "0" to the PCI computer. If the Expansion ROM base address register is presented as a read only register with all bits set to "0", the PCI computer concludes that no Expansion ROM exists on the add-in card. If the Expansion ROM is presented as a read/write register with non-zero values, the PCI computer concludes that an Expansion ROM exists and "shadows" its contents into the memory of the PCI computer.
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申请公布号 |
WO9637842(A1) |
申请公布日期 |
1996.11.28 |
申请号 |
WO1996EP01858 |
申请日期 |
1996.05.03 |
申请人 |
INTERNATIONAL BUSINESS MACHINES CORPORATION;IBM DEUTSCHLAND INFORMATIONSSYSTEME GMBH |
发明人 |
COHEN, ARIEL;HOLLAND, WILLIAM, GAVIN;LOGAN, JOSEPH, FRANKLIN;PARASH, AVI |
分类号 |
G06F13/36;G06F12/06;G06F13/14;(IPC1-7):G06F12/06 |
主分类号 |
G06F13/36 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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