Intel mcs-48 manual Xtali, Rom

Models: mcs-48

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APPLICATION EXAMPLES

 

 

+5V

GND

 

 

 

 

 

 

 

VeeI:l~Voo VssL

Pl0

 

 

 

 

2

 

 

 

 

 

 

 

 

Pll fllL

 

 

 

.-e- XTALI

 

 

 

 

~

 

 

 

P12

30

 

 

 

3

 

 

P13

 

 

 

 

 

~)

 

 

rll =r

XTAL 2

 

P14

~

I/O

 

 

 

 

 

 

PIS &-

 

 

 

:~ RESET

 

P16

~

 

 

 

 

P17

~

 

 

 

 

7

 

 

P20

21

 

 

 

 

 

EA

8049

P21

22

 

 

 

-==

 

 

8048

P22

23

 

 

 

5

 

8748

P23

~~}I/O

 

 

NC - SS

8035'

P24

~ A8

 

 

 

8039'

P25

 

 

 

 

P26 rR-

 

22

A9

 

 

 

 

P27

r1lL

 

23

A10

 

1

 

 

 

 

 

 

 

 

DBO 12

 

12

ADO

 

 

TO

 

 

 

39

 

 

DBI

13

 

13

ADI

 

 

 

14

 

{-

 

 

 

 

14

AD2

 

 

 

 

 

+5V GND

40 15 20 11

Vee Voo vss EE

PAO ~ PAl ~

PA2 ~ 27

PA3 2B PA4 29 PAS 30-

INPUT ~ T1

 

 

 

DB2

 

 

 

 

 

 

DB3 15

15

AD3

INT

 

 

 

DB4 16

16

AD4

 

 

 

 

DB5 17

17

ADS

 

 

 

 

DB6 18

18

AD6

 

 

 

 

DB7 19

19

AD7

ALE PSEN PROG WR iffi

8

 

11

9

 

 

 

lOR

125

110

18

 

 

 

 

 

 

 

 

 

 

10

lOW

 

 

 

 

 

 

 

 

 

 

 

9

RD

 

 

 

 

 

 

 

 

 

 

 

11

ALE

 

 

 

 

 

 

*EA = 5V FOR 8035/8039

 

 

 

 

2

 

 

 

 

+5V _ CE

,

 

 

CAN BE SUPPLIED BY SYSTEM

---!RESET

 

 

 

RESET OR PORT LINE OF 8048

 

 

8355

8755A

2K x 8

ROM

.E 13 16

-=-NC NC

PA6 'jf-

PA7 =-

PBO &--PBl ~ PB2 ~ PB3 ~

PB4 ~ PBS &-

PB6 ~ PB7 ~

I/O

External I/O ports are addressed as data memory PA=OO PB=01

If the 8048'sinternal Program Memory is used this configuration will result in the upper 1K of external memory being addressed before the lower 1K. Inverting A10 will correct this if necessary. This inversion is not necessary if the 8049 is used.

ADDING A PROGRAM MEMORY AND 1/0 EXPANDER

5-8

Page 119
Image 119
Intel mcs-48 manual Xtali, Rom