High Speed 1 OUT of 8 Binary Decoder

Schottky Bipolar 8205

•110 Port or Memory Selector

•Simple Expansion - Enable Inputs

•High Speed Schottky Bipolar Technology - 18ns Max. Delay

•Directly Compatible with TTL Logic Circuits

•Low Input Load Current - .25 mA max., 1/6 Standard TTL Input Load

•Minimum Line Reflection - Low Voltage Diode Input Clamp

•Outputs Sink 10 mA min.

•16-Pin Dual-In-Line Ceramic or Plastic Package

The 8205 decoder can be used for expansion of systems which utilize input ports, output ports, and mem- ory components with active low chip select input. When the 8205 is enabled, one of its eight outputs goes "Iow", thus a single row of a memory system is selected. The 3 chip enable inputs on the 8205 allow easy system expansion. For very large systems, 8205 decoders can be cascaded such that each decoder can drive eight other decoders for arbitrary memory expansions.

The Intel@8205 is packaged in"a standard 16 pin dual-in-line package; and its performance is specified over the temperature range of O°C to +75°C, ambient. The use of Schottky barrier diode clamped transistors to obtain fast switching speeds results in higher performance than equivalent devices made with a gold diffu- sion process.

PIN CONFIGURATION

Ao		16	V-cc
A1	2	15	°0
A2	3	14	0 1
E1	4	13	°2
		8205
E2	5	12	°3
E3	6	11	0 4
0 7	7	10	°5
GRD	8	9	°6
			°6

PIN NAMES

AO-A2 ADDRESS INPUTS E,- E3 ENABLE INPUTS °0.°7 DECODED OUTPUTS

LOGIC SYMBOL

8205

ADDRESS

ENABLE

OUTPUTS

Ao A, A2

E, E2 E3 0

3 4

H L H H H H H H H

H L L L L H H l

H H H H H H

L H L l

L H H H L H H H H H

H H L L

H H H H L H H H H

H L

H H H H H L H H H

H L

H H H H H H L H

H H L

H H H H H H H L

H H H L

L H H H H H H

H H L

H ...

X X X H L

H H H H H H H H

X X X L H L H H H H H H H H

X X X H H L

H H H H H H H H

X X X H L

H H H H H H H H H

X X X L

H H H H H H H H H H

X X X H H H H H H H H H H

5-147

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.

Intel 8080 manual High Speed 1 OUT of 8 Binary Decoder

Models: 8080

Schottky Bipolar 8205