DP8430V datasheet(13/56 Pages) NSC

tên linh kiện	DP8430V

Giải thích chi tiết về linh kiện	microCMOS Programmable 256k/1M/4M Dynamic RAM Controller/Drivers

PDF	56 Pages

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nhà sản xuất	NSC [National Semiconductor (TI)]

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40 Port A Access Modes (Continued)

42 ACCESS MODE 1

Mode 1 asynchronous access is selected by asserting the

input B1 during programming (B1e1) This mode allows ac-

cesses to start immediately from the access request input

ADS To initiate a Mode 1 access CS is asserted followed

by ADS asserted If precharge time was met a refresh of

the DRAM or a Port B access was not in progress the RAS

(RASs) would be asserted from ADS being asserted If a

refresh or Port B access is in progress or precharge time is

required the controller will wait until these events have tak-

en place and assert RAS (RASs) from the next rising edge

of clock

When ADS is asserted or sometime after AREQ must be

asserted At this time ADS can be negated and AREQ will

continue the access Also ADS can continue to be asserted

after AREQ has been asserted and negated however a

new access will not start until ADS is negated and asserted

again When address pipelining is not implemented ADS

and AREQ can be tied together

The access will end when AREQ is negated

TLF11118 – 9

FIGURE 8b Access Mode 1

DP8430V bảng dữ liệu(PDF) 13 Page - National Semiconductor (TI)