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~National
~ Semiconductor
Preliminary
JULY 1978.
-Z
~
INS8257 Programmable DMA Controller
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General Description
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The INS8257 is a Direct Memory Access (DMA) con· troller contained in a standard 40·pin dual·in·line
The channel control registers consist of four 16·bit DMA address registers and four 16·bit terminal count
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package. The chip, which is fabricated using
(TC) registers. These registers provide the means for
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N·channel silicon gate technology, performs direct
con·trolling DMA transfers on their respective
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control of high speed data transfers to and from
channels.
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memory over four separate channels. Data can be transferred in single bytes or in blocks containing up
The auto load feature permits the repetition of block
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to 16,384 bytes.
INS8257 Datasheet
