Fully Decoded Random Access BIT Dynamic Memory

Silicon Gate MOS 81078·4

FULLY DECODED RANDOM ACCESS

4096 BIT DYNAMIC MEMORY

*Access Time··270 ns max.

*Read, Write Cycle Times--470 ns max.

*Refresh Period -- 2 ms

• Low Cost Per Bit	• Address Registers
• Low Standby Power	Incorporated on the Chip
• Easy System Interface	• Simple Memory Expansion-
• Only One High Voltage	Chip Select Input Lead
Input Signal- Chip Enable	• Fully Decoded - On Chip
• TTL Compatible -- All Address,	Address Decode
Data, Write Enable,	• Output is Three State and
Chip Select Inputs	TTL Compatible
• Read-Modify-Write Cycle	• Industry Standard 22-Pin
Time _. 590 ns	Configuration

The Intel 81078 is a 4096 word by 1 bit dynamic n-channel MOS RAM. It was designed for memory applications where very low cost and large bit storage are important design objectives. The 81078 uses dynamic circuitry which reduces the standby power dissipation.

Reading information from the memory is non-destructive. Refreshing is most easily accomplished by performing one read cycle on each of the 64 row addresses. Each row address must be refreshed every two milliseconds. The memory is re- freshed whether Chip Select is a logic one or a logic zero.

The 81078 is fabricated with n-channel silicon gate technology. This technology allows the design and production of high performance, easy to use MOS circuits and provides a higher functional density on a monolithic chip than other MOS technologies. The 81078 uses a single transistor cell to achieve high speed and low cost. It is a replacement for the 81078.

PIN CONFIGURATION

LOGIC SYMBOL

BLOCK DIAGRAM

81078

Vee

Vss

0----.

.......0

"be

0----.

Vee

MEMORY

ROW DECODE

A,o

A 2

DIN

ARRAY

~ Vss

and BUFFER

0----.

64 x 64

.......0

"BB

Vee

~ 0----.

o.N

DOUT

f64

DouT

A.1

A,o

0----.

TIMING

COLUMN

CONTROL

AMPLIFIERS

GENERATOR

Vee

PIN NAMES

ADDRESS INPUTS*

VBB

POWER (-5V)

DIN

0----.

Ao-A"

0----.

I/O

CHIP ENABLE

Vee

POWER (+5V)

0----.

CHIP SELECT

VOO

POWER (+12V)

DIN

DATA INPUT

Vss

GROUND

DOUT

DATA OUTPUT

WRITE ENABLE

NOT CONNECTED

*Refresh Address Ao-As'

5-83

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 Fully Decoded Random Access BIT Dynamic Memory

Models: 8080

FULLY DECODED RANDOM ACCESS

4096 BIT DYNAMIC MEMORY

PIN CONFIGURATION

LOGIC SYMBOL

BLOCK DIAGRAM

f64

8080 specifications