October 5, 2020

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: Nirn Kale
Country: Tanzania
Language: English (Spanish)
Genre: History
Published (Last): 4 September 2004
Pages: 496
PDF File Size: 14.49 Mb
ePub File Size: 1.57 Mb
ISBN: 838-4-72966-818-8
Downloads: 65022
Price: Free* [*Free Regsitration Required]
Uploader: Nale

This is an active low signal. When the reset pin is activated by an external key all the internal operations are suspended and the program counter is cleared and the program execution begins at zero memory address.

Microprocessor Pin Diagram Explained

This is a Read control signal active low. The serial data on this pin is loaded into the seventh bit of the accumulator when RIM instruction is executed. It has the highest priority among the interrupts.

A peripheral may be a LCD display or analog to digital converter or any other. When HOLD pin is activated by an external signal the microprocessor relinquishes control of buses and allows the external pheripheral to use them.

The pins A8-A15 denote the address bus. Its frequency is always same as the frequency at which the microprocessor operates.


The serial data on this pin delivers its output to the seventh bit of the accumulator when SIM instruction is executed. This is provided by CLK pin. They insert an internal restart function automatically. Suppose if analog to digital converter is using the address and data bus and if LCD requests the use of address and data bus by giving HOLD signal, then the microprocessor transfers the control to the LCD as soon as the current cycle is over.

This indicates if any other device is requesting the use of address and data bus.

8085 Microprocessor Pin Diagram Explained

It cannot mocroprocessor enabled or disabled using a program. When it is high. Power supply and Frequency signals: The lower order address bus is added to memory or any external latch.

In the previous article we saw how ALE helps in demultiplexing the lower order address and data bus. Consider we have an address to be processed. It has the lowest priority among the interrupts. This pin provides serial input data.

Microprocessor Pin Configuration

Pins like Vcc and ground are classified under this type. Introduction In the previous articles we saw about the architecture of microprocessor.

They are used for the most significant bit of memory address. These are nothing but the restart interrupts.

S0 and S1 are status signals which provides different status and functions depending on their status. The frequency is internally divided by two; therefore to operate a system at 3 MHz, the crystal should have frequency of 6 Mhz. After the LCD process is over, the control is transferred back to analog ppin digital converter.

  IEC 62351-7 PDF

Signals associated with the lower order address bus and time multiplexed higher order address bus comes under this type of signals.

This is used to acknowledge interrupt. This signal goes high during the first microprocdssor cycle and enables the lower order address bits. Signals associated with data bus comes under this type. These pins are used for least significant bits of address bus in the first machine clock cycle and used as explanztion bus for second and third clock cycle.

Pin Diagram and Pin description of 8085 Microprocessor

So the first clock cycle means the first transition of pulse from 0volts to 5 volts and then back micropdocessor 0 volts. Control and Status Signals: This is an active high, serial input port pin, used to accept serial 1 bit data under software control. INTR is an interrupt request signal. Pin Diagram of Microprocessor and its description is as follows: They have higher priority than the INTR interrupt.