Evalue Technology ECM-3610, User Manual

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ECM-3610/3610L
ECM-3610/3610L User’s Manual 137
DMA-channel Usage
The DMA circuitry incorporates the functionality of two 8237 DMA controllers with seven
programmable channels. The controllers are referenced DMA Controller 1 for channels 0-
3 and DMA Controller 2 for channels 4-7. Channel 4 is by default used to cascade the two
controllers.
Channels 0-3 are hardwired to 8-bit count-by-bytes transfers and channels 5-7 to 16-bit
count-by-bytes transfers.
The onboard VIA VT82C686B provides 24-bit addressing with the 16 least significant bits
[15:0] in the Current register and the most significant bits [24:16] in the Page register.
DMA-channel Description Note
DMA0
DMA1
DMA2 Standard Floppy Disk Controller
DMA3
DMA4 Direct memory access controller
DMA5
DMA6
DMA7
Note:
The usage of these DMA-channels depends on the choices made in the Evalue
setup screen. The DMA-channels are fully usable for both PC/104 interface and
PCI slot if the corresponding on-board unit is disabled in the setup screen.