Schottky Bipolar 8212

EIGHT-BIT INPUT/OUTPUT PORT

•Fully Parallel 8-Bit Data Register and Buffer

•Service Request Flip-Flop for Interrupt Generation

•Low Input Load Current -

.25 mA Max.

•Three State Outputs

•Outputs Sink 1.5 mA

•3.65V Output High Voltage for Direct Interface to 8080 CPU or 8008 CPU

•Asynchronous Register Clear

•Replaces Buffers, Latches and Multiplexers in Micro- computer Systems

•Reduces System Package Count

The 8212 input/output port consists of an 8-bit latch with 3-state output buffers along with control and device selection logic. Also included is a service request flip-flop for the generation and control of interrupts to the microprocessor.

The device is multimode in nature. It can be used to implement latches, gated buffers or multiplexers. Thus, all of the princi- pal peripheral and input/output functions of a microcomputer system can be implemented with this device.

PIN CONFIGURATI"ON

LOGIC DIAGRAM

 

 

SERVICE REQUEST FF

OS1

vee

\

MO

INT

DEVICE SELECTION

01,

Dl a

-~

DO,

OOa

[DOS1

I!D OS2

01 2

01 7

 

0°2

0°7

~ MO ---- + -........L-~

 

 

01 3

01 6

[i> STB ---- ... ----

00 3

0°6

OUTPUT

01 4

015

BUFFER

 

0°4

0°5

 

STB

CLR

 

GND

DS2

 

11> 01 3 -------....................

 

PIN NAMES

[[> 01 4 ---------

+--

+-4

 

 

 

 

01,.01&

DATA IN

[9DI5-------

~

 

 

 

 

.......

oo,-DOa DATA OUT

 

 

 

DSi-DS2 DEVICE SELECT

 

 

 

MD

MODE

 

 

 

STB

STROBE

 

 

 

INT

INTERRUPT (ACTIVE LOW)

 

 

 

CLR

CLEAR (ACTIVE LOW)

 

 

 

 

 

[g> 01 8 --------- 1 -

 

 

(ACTIVE LOW)

 

 

5-101

Page 168 Page 170
Page 169
Image 169
Intel 8080 manual EIGHT-BIT INPUT/OUTPUT Port, PIN Configuration Logic Diagram
Page 168 Page 170

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.
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