inter

8080A/8080A·1/8080A·2

8·BIT N·CHANNEL MICROPROCESSOR

TTL Drive Capability

2 lAS ( - 1:1.3 lAs, - 2:1.5 lAs) Instruction Cycle

Powerful Problem Solving Instruction Set

6 General Purpose Registers and an Accumulator

16·Bit Program Counter for Directly Addressing up to 64K Bytes of Memory

16·Bit Stack Pointer and Stack Manipulation Instructions for Rapid Switching of the Program Environment

Decimal, Binary, and Double Precision Arithmetic

Ability to Provide Priority Vectored Interrupts

512 Directly Addressed 1/0 Ports

Available in EXPRESS

- Standard Temperature Range

The Intel® 8080A is a complete 8-bit parallel central processing unit (CPU). It is fabricated on a single LSI chip using Intel'sn-channel silicon gate MOS process. This offers th~ user a high performance solution to control and processing applications.

The 8080A contains 6 8-bit general purpose working registers and an accumulator. The 6 general purpose registers may be addressed individually or in pairs providing both single and double precision operators. Arithmetic and logical instructions set or reset 4 testable flags. A fifth flag provides decimal arithmetic operation.

The 8080A has an external stack feature wherein any porti'onof memory may be used as a last in/first out stack to store/retrieve the contents of the accumulator, flags, program counter, and all of the 6 general purpose registers. The 16-bit stack pointer controls the addressing of this external stack. This stack gives the 8080A the ability to easily handle multiple level priority interrupts by rapidly storing and restoring processor status. It also provides almost unlimited subroutine nesting.

This microprocessor has been designed to simplify systems design. Separate 16-line address and a-line bidirectional data busses are used to facilitate easy interface to memory and I/O. Signals to control the interface to memory and I/O are provided directly by the 8080A. Ultimate control of the address and data busses resides with the HOLD signal. It provides the ability to suspend processor operation and force the address and data busses into a high impedance state. This permits OR-tying these busses with other controlling devices for (DMA) direct memory access or multi-processor operation.

NOTE:

The 8080A is functionally and electrically compatible with the Intel® 8080.

 

RESET

A3

 

HOLD

+,2V

 

 

 

INT

A2

 

 

A,

 

 

Ao

 

 

WAIT

 

WR

READY

 

0,

 

SYNC

 

 

 

+5V

HLDA

Figure 1. Block Diagram

Figure 2.

Pin Configuration

6-1

Page 110
Image 110
Intel MCS-80/85 manual Inter

MCS-80/85 specifications

The Intel MCS-80/85 family, introduced in the late 1970s, is a seminal collection of microprocessors that played a pivotal role in the early days of computing. The MCS-80 series, initially targeting embedded systems and control applications, gained remarkable attention due to its innovative architecture and flexible programming capabilities.

The MCS-80 family is anchored by the 8080 microprocessor, which was one of the first fully integrated 8-bit microprocessors. Released in 1974, the 8080 operated at clock speeds ranging from 2 MHz to 3 MHz and featured a 16-bit address bus capable of addressing up to 64KB of memory. The processor’s instruction set included around 78 instructions, providing extensive capabilities for data manipulation, logic operations, and branching.

Complementing the 8080 was a suite of support chips, forming the MCS-80 platform. The most notable among them was the 8155, which integrated a static RAM, I/O ports, and a timer, tailored for ease of designing systems around the 8080. Other support chips included the 8085, which provided improvements with an integrated clock generator, making it compatible with more modern designs and applications.

The MCS-85 series, on the other hand, revolves around the 8085 microprocessor, which provided a more advanced architecture. The 8085 operated at clock speeds of up to 6 MHz and came with a 16-bit address bus, similar to its predecessor. However, it introduced more sophisticated features, including an enhanced instruction set and support for interrupt-driven programming. These enhancements made the 8085 especially appealing to developers working in real-time processing environments.

The MCS-80/85 family utilized NMOS technology, known for its lower power consumption and higher performance compared to previous technologies like TTL. The family’s architecture allowed for easy interfacing with a variety of peripherals, making it a favorite for educational institutions and hobbyists embarking on computer engineering projects.

With its robustness, versatility, and affordability, the Intel MCS-80/85 microprocessors laid the groundwork for many subsequent microcomputer systems and applications. The legacy of this powerful family continues to influence modern microprocessor design, emphasizing the importance of reliable architecture in a rapidly evolving technology landscape.