How does the Address Strobe Line work when doing Block Mode Transfers? Primary Software: Driver Software>>NI-VXI/VISAPrimary Software Version: 1.1 Primary Software Fixed Version: N/A Secondary Software: N/A Hardware: VXI/VME/MXI>>MXI Interfaces>>PCI-MXI-2
Problem: The address strobe line remains low when doing VXI block transfers. Why is this? Solution: The spec says that it will remain low up to 256 transfers at which time the bus is given up to the next bus master that is requesting the bus. If the transfer size is larger than 256 transfers, the bus master must arbitrate for the bus again, which means that address strobe could potentially toggle after 256 and then drop again. In a MXI-2 controller, you could see the address line toggle up and down during a block transfer. The reason is that data is transferred from the computer thru the MXI cable into the VXI/VME-MXI-2 which itself does the transfer. At that point the data is propagated from the VXI/VME-MXI-2 onto the VXI/VME backplane. Hence there is a slight propagation delay. Related Links: Attachments:
Report Date: 07/30/1998 Last Updated: 11/11/2005 Document ID: 1BT7L7QR |
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