Silicon Gate MOS 8702A

2048 BIT ERASABLE AND ELECTRICALLY REPROGRAMMABLE READ ONLY MEMORY

Access Time -1.3~sec Max.

Fast Programming - 2 Minutes for All 2048 Bits

Fully Decoded, 256 x 8 Organization

Static MOS - No Clocks Required

Inputs and Outputs TTL Compatible

Three-State Output - OR-Tie Capability

Simple Memory Expansion Chip Select Input Lead

The 8702A is a 256 word by 8 bit electrically programmable ROM ideally suited for microcomputer system development where fast turn-around and pattern experimentation are important. The 8702A undergoes complete programming and functional testing on each bit position prior to shipment, thus insuring 100% programmability.

The 8702A is packaged in a 24 pin dual-in line package with a transparent quartz lid. The transparent quartz lid allows the user to expose the chip to ultraviolet light to erase the bit pattern. A new pattern can then be written into the device. This procedure can be repeated as many times as required.

The circuitry of the 8702A is entirely static; no clocks are required.

A pin-for-pin metal mask programmed ROM, the Intel 8302, is ideal for large volume production runs ~f systems initially using the 8702A.

The 8702A is fabricated with silicon gate technology. This low threshold technology allows the design and production of higher performance MOS circuits and provides a higher functional density on a monolithic chip than conventional MOS technologies.

 

PIN CONFIGURATION

 

BLOCK DIAGRAM

A2

 

 

DATA OUT 1 DATA OUT 8

 

 

Voo

 

A,

 

 

Vee

 

Ao

 

 

Vee

OUTPUT

 

 

BUFFERS

*DATA OUT 1

 

 

A3

 

*DATA OUT 2

 

 

A4

2048 BIT

 

 

 

 

*DATA OUT 3

 

 

PROGRAM

PROM MATRIX

 

 

As

(256 X 8)

 

 

 

 

*DATA OUT 4

 

 

A6

 

*DATA OUT 5

 

 

A7

 

*DATA OUT 6

9

16

VGG

 

*DATA OUT 7

10

15

Vee

 

*DATA OUT 8

11 (MSB)

14

CS

 

Vee

12

13

PROGRAM

 

*THIS PIN IS THE DATA INPUT LEAD DURING PROGRAMMING.

PIN NAMES

Ao-A7ADDRESS INPUTS

CS

CHIP SELECT INPUT

001- 002 DATA OUTPUTS

5-37

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Intel 8080 manual Silicon Gate MOS 8702A

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.