AR-B1479 User’s Guide
11
2.6 DMA CONTROLLER
l DMA channel
l 2X8237/AT compatible 7-channel DMA controller.
l 2X8259/AT compatible interrupt Controller.
16 interrupt inputs – ISA and PCI.
l Three 8254 compatible Timer/Counters.
l Co-processor error support logic.
The figure below describes a complete implementation of the external glue logic for DMA Request time-
multiplexing and DMA Acknowledge demultiplexing. Like for the interrupt lines, this logic can be simplified when
only few DMA channels are used in the application. This glue logic is not needed in Local bus mode and it does not
support DMA transfers.
Typical DMA multiplexing and demultiplexing
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