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ISA总线上的AEN是什么？时序关系？ |
| 发布时间:2001年7月5日 点击次数:4313 |
| 来源: 作者: |
Intel 说法： AEN： ADDRESS ENABLE. AEN is asserted during DMA cycles to prevent I/O slaves from misinterpreting DMA cycles as valid I/O cycles. When negated, AEN indicates that an I/O slave may respond to address and I/O commands. When asserted, AEN informs I/O resources on the ISA bus that a DMA transfer is occurring. This signal is also driven high during PIIX4 initiated refresh cycles |
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