Schottky Bipolar 8214

PRIORITY INTERRUPT CONTROL UNIT

•

Eight Priority Levels

•

Fully Expandable

•

Current Status Register

•

High Performance (50ns)

•

Priority Comparator

•

24-Pin Dual In-Line Package

The 8214 is an eight level priority interrupt control unit designed to simplify interrupt driven microcomputer systems.

The PICU can accept eight requesting levels; determine the highest priority, compare this priority to a soft- ware controlled current status register and issue an interrupt to the system along with vector information to identify the service routine.

The 8214 is fully expandable by the use of open collector interrupt output and vector information. Control signals are also provided to simplify this function.

The PICU is designed to support a wide variety of vectored interrupt structures and reduce package count in interrupt driven microcomputer systems.

PIN CONFIGURATION

Bo

 

24

Vee

B,

2

23

ECS

B2

3

22

R7

SGS

4

21

R6

INT

5

20

Rs

elK

6

19

R4

 

 

8214

R3

INTE

 

18

Ao

8

17

R2

A,

9

16

R,

A2

10

15

Ro

ElR

11

14

ENLG

GND

12

13

ETLG

 

PIN NAMES

INPUTS

 

 

Ro·R7

REQUEST LEVELS (R7 HIGHEST PRIORITY)

Bo·B2

CURRENT STATUS

 

SGS

STATUS GROUP SELECT

 

ECS

ENABLE CURRENT STA"fUS

INTE

INTERRUPT ENABLE

 

CLK

CLOCK (tNT F·F)

 

ELR

ENABLE LEVEL READ

 

E1'\.G

ENABLE THIS LEVEL GROUP

OUTPUTS:

 

J-OPEN

Ao·A2

REQUEST LEVELS

INT

INTERRUPT (ACT. LOW)

COLLECTOR

ENLG

ENABLE NEXT LEVEL GROUP

 

 

LOGIC DIAGRAM

[TI>

ElR

 

[}DETlG--

 

 

Ro

REQUEST ACTIVITY

l!P

(OPEN COllECTOR)

~ R,

~ [D

ITI>

R;

~ R;

~ CD

[1D

~

 

~ ~

A2

~ ~

}A

~ ~

 

 

A>B

IT>

60

}B

ED

~

[I>

S;

 

ED

SGS

PRIORITY

~ ECS

COMPARATOR

 

IT> INTE ------------

~

[]> ClK-------------

~

5-153

Page 222 Page 224
Page 223
Image 223
Intel 8080 manual ~ R, ~ ~, PIN Configuration
Page 222 Page 224

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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