Intel 8080 manual DalN-t?!NrJ, 1G~D L-~

Models: 8080

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SCHOTTKY BIPOLAR 8212

(See Note 1)

AO - '

8080

 

A1 --+-

 

:: -

ST;~;T:¢ST:212 tt:7:::~~llllltnn~

8212

=> ~:~~T

 

~ --0 E2

 

ADDRESS .:...

A2 --+-

8205

::=:-

 

 

 

BUS

 

~ ~ E1

 

 

 

 

 

 

Vee- ..E3__..

 

~;:N~~- :IIII[_~L~ee?

 

 

 

I/O DEVICE

 

 

 

 

 

 

 

 

 

 

SELECTOR

 

 

 

 

 

 

INP --......---- t - t - t - t - t - + -- + - t ------------ + - 6

 

 

 

 

 

 

 

STROBE 2 --- .STB

 

 

 

 

 

 

 

INPUT ~

 

~ OUTPUT

STATUS

 

 

 

 

PORT 2 L-Y8212

8212

BITS

-

 

 

 

 

 

W PORT 2

~ CLR

_ OUT ----t------r-t-t-t-t----ir+-t-----------+--+----1~:::::f_4

INT --------004----------1

 

ST;;;;T::: ST:212

m::ili::~Jtmm:~

8212

 

 

 

 

 

r-

- ,

_----L.-,I-<~J11INT CLR 0-<1

-Y[[~\!

. : CLR

 

 

 

 

 

. 1G~D L - _

 

,_-.J Vee

 

 

 

 

 

I

I

:::[:[

 

 

BUFFERED

 

 

I

I

 

 

DATA

 

 

I

I

 

 

 

 

 

 

 

 

BUS

 

Vee I

STROBE 4 -- .STB

 

Ill::

 

 

 

 

 

~

I

I

 

 

8212

 

 

 

 

I

1 IO-++++-.-.....~

PORT 4 L.-,I

8212

ttm::zb ill\:,z:Zht~

 

 

 

 

 

I

I

 

 

 

 

 

 

 

 

 

 

~

I

0 '1IO-++++----4~

INPUT ~

 

 

 

 

 

8080 -- ... J ..

8212

 

 

~

I

2 1O-++++---oIt--

 

 

 

y ~f

y

 

D:J:~!I.

8212

~ H

3 IO-++++-.....-~

 

 

 

 

 

-

~

4 1O-++++---oIt ---------<:::JIINT CLR ~

 

_~L:ee

 

 

 

 

=:

~

 

1G~D L-~

:111

 

 

 

 

-

--I

5 1O-++++---oIt--_

 

 

 

 

 

 

 

I I

................

I

I

 

 

 

:::::

 

 

DalN-t?!NrJ

v~e

 

I:

i

ST;~;;~¢

ST:212

~m:~~j!II!:w::7::~3

8212

 

 

 

GND

I

I

 

 

 

I

I

 

 

 

 

 

 

L __ II_ ..I

~OUTPUT

W PORT 3

Y

~OUTPUT

W PORT 4

y

t> ~~~~~T

 

INTERRUPT

~~~~~_.

I!!!!

-~~eI

 

8212

INSTRUCTION

ST;;;;T:¢

ST:2~::::::::::::::::::::::~~II::::::::::::::::::::?

8212

hi" PORT 6

u +--.s>

PORT (RST)

INTERRUPT

 

 

I

 

 

 

 

 

 

 

 

PRIORITY

 

 

 

 

 

 

 

 

ENCODER &

 

 

 

 

 

~ OUTPUT

GND

GENERATING

 

 

 

 

 

 

INT ----- .. ---- t:

LOGIC CIRCUITS

.......------<=.11 INT CLR ~~

:~:~:

~

CLR

 

BUS DRIVER

(USER DESIGNED)

 

1G~D L - _

\l~\l

-~ Vee I

 

ACK

 

 

 

 

 

 

BI-DI RECTIONAL

 

 

 

 

 

 

 

 

 

 

 

STROBE 7 ---+-

STB

 

 

 

 

 

 

 

 

8212

 

 

8212

~OUTPUT

 

 

 

 

 

 

 

 

W PORT 7

SYSTEM--.....-

RESET

Note 1. This basic I/O configuration for the 8080 can be expanded to 256 input devices and 256 output devices all using 8212 and the appropriate decoding.

5-108

Page 176
Image 176
Intel 8080 manual DalN-t?!NrJ, 1G~D L-~

8080 specifications

The Intel 8085 and 8080 microprocessors were groundbreaking innovations in the world of computing, paving the way for future microprocessor development and personal computing.

The Intel 8080, introduced in 1974, was an 8-bit microprocessor that played a fundamental role in the early days of personal computing. With a 16-bit address bus, it had the capability to address 64 KB of memory. Running at clock speeds of 2 MHz, the 8080 was notable for its instruction set, which included 78 instructions and 246 opcodes. It supported a range of addressing modes including direct, indirect, and register addressing. The 8080 was compatible with a variety of peripherals and played a crucial role in the development of many early computers.

The microprocessor's architecture was based on a simple and efficient design, making it accessible for hobbyists and engineers alike. It included an 8-bit accumulator, which allowed for data manipulation and storage during processing. Additionally, the 8080 featured registers like the program counter and stack pointer, which facilitated program flow control and data management. Its ability to handle interrupts also made it suitable for multitasking applications.

The Intel 8085, introduced in 1976, was an enhancement of the 8080 microprocessor. It maintained a similar architecture but included several key improvements. Notably, the 8085 had a built-in clock oscillator, simplifying system design by eliminating the need for external clock circuitry. It also featured a 5-bit control signal for status line management, which allowed for more flexible interfacing with peripheral devices. The 8085 was capable of running at speeds of up to 3 MHz and had an extended instruction set with 74 instructions.

One of the standout features of the 8085 was its support for 5 extra instructions for stack manipulation and I/O operations, which optimized the programming process. Additionally, it supported serial communication, making it suitable for interfacing with external devices. Its 16-bit address bus retained the 64 KB memory addressing capability of its predecessor.

Both the 8080 and 8085 microprocessors laid the groundwork for more advanced microprocessors in the years that followed. They demonstrated the potential of integrated circuits in computing and influenced the design and architecture of subsequent Intel microprocessors. Their legacy endures in the way they revolutionized computing, making technology accessible to a broader audience, and their influence is still felt in the design and architecture of modern microprocessors today.