1. 1 Q.1) Draw & Explain the Pin-Diagram of Microprocessor in Detail? Ans: The Microprocessor is an 8-Bit general-purpose. is a 40 pin IC, The signals from the pins can be grouped as follows Power supply and clock signals,Address bus,Data bus Pin Diagram and Pin description of It is used to know the type of current operation of the microprocessor. Microprocessor – All concepts, programming, interfacing and applications explained.

Author: Meshura Vudorn
Country: Bolivia
Language: English (Spanish)
Genre: Technology
Published (Last): 25 January 2015
Pages: 187
PDF File Size: 8.64 Mb
ePub File Size: 10.99 Mb
ISBN: 581-7-60172-745-4
Downloads: 19497
Price: Free* [*Free Regsitration Required]
Uploader: Teshicage

In explanatioj previous article we saw how ALE helps in demultiplexing the lower order address and data bus. They insert an internal restart function automatically.

The pins A8-A15 denote the address bus. The serial data on this pin is loaded into the seventh bit of the accumulator when RIM instruction is executed. They have higher priority than the INTR interrupt. All the above mentioned interrupts are maskable interrupts.

Microprocessor – 8085 Pin Configuration

They are used for the most significant bit of microprocessoe address. A peripheral may be a LCD display or analog to digital converter or any other. This is used to acknowledge interrupt. This is a non-maskable interrupt and has highest priority. These pins are used for least significant bits of address bus in the first machine clock cycle and used as data bus for second and third clock cycle.


This is an active high, serial input port pin, used to accept serial 1 bit data under software control.

Consider two peripheral devices. AD 0 -AD 7. That is, an operation is performed when the signal goes low. In the previous articles we saw about the architecture of microprocessor. Signals associated with data bus comes under this type. This pin provides the serial output data.

It indicates whether the HOLD signal explnaation received or not. S0 and S1 are status signals which provides different mifroprocessor and functions depending on their status. INTR is an interrupt request signal. Whenever the microprocessor receives interrupt signal.

Pin Diagram and Pin description of Microprocessor

The frequency is internally divided by two; therefore to operate a system at 3 MHz, the crystal microprocessr have frequency of 6 Mhz. In this article let us discuss in detail about the various signals involved in transferring data and executing instructions in microprocessor. In simple words clock cycle refers to the transition between o volts to 5 volts and back to 0 volts. This signal goes high during the first clock cycle and enables the lower order address bits.

This distinguishes whether the address is for memory or IO. Its frequency is always same as the frequency at which the microprocessor operates. This is a Read control signal active low.

Classification of Signals The various signals in a microprocessor microprocfssor be classified as Power supply and Frequency signals: While the pin goes low, the address is assigned for the memory. It has the highest priority among the interrupts. Pin-wise description of is as follows. The lower order address bus is added to memory or any external latch.


It has to be acknowledged. So the first clock cycle means the first transition of pulse from 0volts to 5 volts and then back to 0 volts. Power supply and Frequency signals: This indicates if any other device is requesting the use of address and data bus. This signal is primarily used to synchronize slower peripherals with the microprocessor. Signals which aids in supplying power and generating frequency are associated with this type.

These are nothing but the restart interrupts.

Pin Diagram and Pin description of

This pin resets the program counter to 0 and resets interrupt enable and HLDA flip-flops. They are time multiplexed. The CPU is held in reset condition until this pin is high. These 8 signal lines are unidirectional and used for most significant bits called higher order address bus of a bit address. Pins like Vcc and ground are classified under this type. It has the lowest priority among the interrupts. Introduction In the previous articles we saw about the architecture of microprocessor.

This is a Write control signal active low.