infel® Silicon Gate MOS 8080A-1

SINGLE CHIP 8-BIT N-CHANNEL MICROPROCESSOR

•TTL Drive Capability

•1.3 J.Ls Instruction Cycle

•Powerful Problem Solving Instruction Set

•Six General Purpose Registers and an Accumulator

•Sixteen Bit Program Counter for Directly Addressing up to 64K Bytes of Memory

•Sixteen 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

The Intel® aOaOA is a complete a-bit parallel central processing unit (CPU). It is fabricated on a single LSI chip using Intel's n-channel silicon gate MOS process. This offers the user a high performance solution to control and processing applications.

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

The aOaOA has an external stack feature wherein any portion of 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 six general purpose registers. The sixteen bit stack pointer controls the addressing of this external stack. This stack gives the 80aOA 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 bi-directional data busses are used to facilitate easy interface to memory and I/O. Signals to control the interface to memory and I/O are pro- vided directly by the aOaOA. 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.

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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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