Figure B.4 512 Kbyte Interface with 150 ns Memory

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

 

 

 

 

27C010-15/28F010-15 Sockets

+ 12 V

 

 

VPP

 

 

 

VPP

 

 

 

 

 

 

GPIO4

 

 

 

 

 

 

Control

 

 

 

 

 

MWE/

 

 

 

 

 

 

 

 

WE

WE

WE

WE

 

 

 

 

MOE/

 

 

 

 

 

 

 

 

 

 

 

OE

OE

OE

OE

 

 

 

 

D[7:0]

D[7:0]

D[7:0]

D[7:0]

MAD[7:0]

 

 

A[7:0]

D[7:0]

 

 

 

 

 

 

 

 

 

Bus

 

VDD

 

 

 

 

 

 

A0

A0

A0

A0

 

 

 

MAD3

4.7 K

 

 

.

.

.

.

 

 

 

A[15:8] .

.

.

.

MAD1

4.7 K

 

 

.

.

.

.

MAD3

4.7 K

 

 

 

 

 

 

LSI53C875A

D0

Q0

 

 

 

 

 

8

HCT374

 

 

 

 

 

MAS0/

D7

Q7

 

 

 

 

 

 

CK

QE

 

 

 

 

 

 

 

 

 

A16

A16

A16

A16

 

D0

Q0

 

CE

CE

CE

CE

8

HCT374

 

 

 

 

 

 

MAS1/

D7

Q7

 

 

 

 

 

 

CK

QE

 

 

 

 

 

MAD[2:0]

 

 

 

 

 

 

 

Bus

D0

Q0

 

 

 

 

 

3

D2

 

A

Y0

 

 

 

MCE/

HCT377

 

 

 

 

 

CK

Q2

B

Y1

 

 

 

 

E

 

 

 

 

 

 

 

Y2

 

 

 

 

 

 

 

 

 

 

 

 

 

GB

Y3

 

 

 

 

 

 

HCT139

 

 

 

Note: MAD2 pulled LOW internally. MAD bus sense logic enabled for 512 Kbytes of slow memory (150 ns devices, additional time required for HCT139 @ 33 MHz). The HCT374s may be replaced with HCT377s.

B-4

External Memory Interface Diagram Examples

Page 310
Image 310
LSI 53C875A technical manual Figure B.4 512 Kbyte Interface with 150 ns Memory