Figure B.3 128 Kbytes, 256 Kbytes, 512 Kbytes, or 1 Mbyte Interface with 150 ns Memory

Optional - for Flash Memory only, not required for EEPROMS.

LSI53C875A

VPP

 

 

+ 12 V

 

 

 

GPIO4

VPP

 

 

 

 

 

 

 

 

 

 

Control

 

 

 

MWE/

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

MOE/

 

 

 

 

 

 

 

 

 

 

 

 

 

MCE/

 

 

 

 

 

MAD[7:0]

 

D[7:0]

 

A[7:0]

Bus

 

 

VDD

MAD3

4.7 K

A[15:8]

 

 

 

A[19:16]

8

D0

Q0

 

HCT374

MAS0/

D7

Q7

 

CK

QE

 

D0

Q0

6

HCT374

D7

Q7

MAS1/

CK

QE

 

MAD[3:0]

D0

Q0

Bus

4

HCT377

D3

Q3

 

CK

 

 

E

 

WE

OE

CE

27C020-15/

28F020-15/

Socket

Note: MAD[2:0] pulled LOW internally. MAD bus sense logic enabled for 128, 256, 512 Kbytes, or 1 Mbyte of fast memory (150 ns devices @ 33 MHz). The HCT374s may be replaced with HCT377s.

External Memory Interface Diagram Examples

B-3

Page 309
Image 309
LSI 53C875A technical manual External Memory Interface Diagram Examples