DP8522A datasheet(23/70 Pages) NSC

Part #	DP8522A

Description	DP8520A/DP8521A/DP8522A microCMOS Programmable 256k/1M/4M Video RAM Controller/Drivers

PDF	70 Pages

Scroll/Zoom	100%

Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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23 / 70 page

60 DP8520A21A22A

Video RAM Support

The DP8520A21A22A provides full support for all access

modes of video RAMs through the addition of three pins

(AVSRLRQ

VSRL

and

DT OE)

the

standard

DP8420A21A22A The access modes of video RAMs can

be split up into two groups video RAM transfer cycles (read

with the serial port in active or in standby mode write and

pseudo write transfer cycles) and non-transfer cycles The

DP8520A21A22A support of video RAMs allows the full

capabilities of the National Semiconductor Advanced

Graphics chip set (DP8500 Series) to be realized See

Fig-

ures 22 23 and 58a

TLF9338 – 52

FIGURE 22 The Video RAM (A Dual Ported Memory)

Ideal solution for graphics frame buffer Screen refresh

can occur at the same time as random access to the

frame buffer for screen update and manipulation

TLF9338 – 56

FIGURE 23 The DP8500 Raster Graphics Processor Interfaced to the DP8520A21A22A Video RAM Controller

DP8522A Datasheet(PDF) 23 Page - National Semiconductor (TI)