Intel mcs-48 manual 8085A Minimum System Configuration, Interval Timer Interrupt Levels, Wr Ad Ale

Models: mcs-48

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8085A MINIMUM

SYSTEM CONFIGURATION

Figure 11 shows a minimum system using three chips, containing:

256 Bytes RAM'

2K Bytes ROM

381/0 Pins

1 Interval Timer

4 Interrupt Levels

 

A8-1S

 

 

ADO-7

 

 

ALE

---.!.

B085A

RD

-

 

WR

 

-

 

 

"

"-

;..v

VCC

101M

 

 

 

 

 

 

 

-

ClK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-

RESET DUTt

 

 

 

 

 

 

READY

,

 

 

 

 

 

 

-

 

 

,

 

 

 

 

 

 

-

 

 

,

 

 

 

 

 

 

 

 

 

,-

 

 

 

 

 

 

 

 

I

TIMER

WR AD ALE

CE" 7

101M

"

7:~~<;

RESET

 

IN

 

 

 

 

 

 

 

 

 

 

 

~

I

 

 

 

 

 

 

 

'-lLATCHES

 

 

 

 

 

 

 

' -- ' --

I

 

 

 

T~~~R_

G CONTROL

~

 

 

 

 

 

 

 

 

256 x 8

I

 

 

 

 

 

 

 

 

RAM

 

 

 

 

8156

 

-

l

 

 

 

 

 

 

 

 

 

 

 

~~cp$

vv~

-

1

,

,

_101

7~~ CE M ALE iIDiOvi elK RS~RDY

8355 JROM ... I/O I

OR

8755 IPROM + lID I

Vee

- NOTE, OPTIONAL CONNECTIONS

B. BB B B

 

Figure 11. 808SA Minimum System Conllguratlon. (Memory Mapped 1/0)

6-90

Page 233
Image 233
Intel mcs-48 manual 8085A Minimum System Configuration, Interval Timer Interrupt Levels, Wr Ad Ale