Messages in this thread | | | Date | Sat, 28 Apr 2001 09:25:05 +0100 | From | Russell King <> | Subject | Re: busmaster question |
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On Sat, Apr 28, 2001 at 01:27:30AM -0500, daniel sheltraw wrote: > I have a busmaster question I am hoping you can help me with. > If a PCI device is acting as a busmaster and the processor initiates a > read/write to another device on the PCI bus while the busmater-device is in > control of the bus what happens to the instructions initiated by the > processor? Are they never seen by the device that the processor > is trying to read/write?
The access by the processor is delayed until the PCI arbiter allows the CPU access to the PCI bus (how long depends on all sorts of things which I won't go into, but its not necessarily held off until the end of the busmaster transfer).
-- Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html
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