In this section we will see how to generate the time delay using 8085 programs. The delay will be used in different places to simulate clocks, or counters or some other area.When the delay subroutine is executed, the microprocessor does not execute other tasks. For the delay we are using the instruction execution times. executing some instructions in a loop, the delay is generated. There are some methods of generating delays. These methods are as follows.Using NOP instructionsUsing 8-bit register as counterUsing 16-bit register pair as counter.Using NOT instructions:One of the main usage of NOP instruction is in delay generation. ... Read More

Now let us see a program of Intel 8085 Microprocessor. In this program we will see how to simulate the decimal up counter.Problem Statement:Write 8085 Assembly language program to simulate decimal up counter.Discussion:In this section we are simulating the decimal up counter. Here the counter will count 100 decimal numbers from 0 to 99. All values will be updated in each 0.5 seconds. For decimal count we are using the DAA instruction.Note: Here for simplicity we are storing the numbers into memory. To simulate it like a counter we can use 7-segment display to show the numbersInput:Here we are not ... Read More

Now let us see a program of Intel 8085 Microprocessor. In this program we will see how to sort a sequence of numbers using selection sort.Problem Statement:Write 8085 Assembly language program to sort a given sequence using selection sort in ascending order. The numbers are stored at 8001H onwards. 8000H is holding the block size.Discussion:In the selection sorting technique, we will choose the minimum or the maximum term from a set of numbers. In this case we are considering the sorting in ascending order, so we are choosing the minimum number. By taking the minimum number, we are swapping it ... Read More

Now let us see a program of Intel 8085 Microprocessor. This program will help us to check a given value is a valid 2 out of 5 code or not.Problem Statement:Write 8085 Assembly language program to check whether a given number is 2 out of five code or not. The number is stored at location 8000H.Discussion:The checking of two out of five code is simple. At first we have to check the higher order three bits are 0 or not. If they are 0, then we will check next five bits. If there are exactly two 1s in these 5-bits, ... Read More

Now let us see a program of Intel 8085 Microprocessor. This program is mainly for subtracting multi Byte numbers.Problem Statement:Write 8085 Assembly language program to add two multi-Byte numbers.Discussion:We are using 3-Byte numbers. The numbers are stored into the memory at location 8001H and 8004H. One additional information is stored at location 8000H. In this place we are storing the Byte count. The result is stored at location 8050H.We are taking the address of first operand block address into DE register pair, and the second operand block address into HL pair. The BC register pair is storing the destination address ... Read More

A Bipolar Junction Transistor (BJT) is a three terminal circuit or device that amplifies flow of current. It is solid state device that flows current in two terminals, i.e., collector and emitter and controlled by third device known as terminal or base terminal. Unlike a normal p-n junction diode, this transistor has two p-n junctions. The basic symbols of BJT are n-type and p-type. Electronic current is conducted by both free electrons and holes in bipolar junction transistor.Terminals of Bipolar Junction TransistorsThere are three terminals in bipolar junction transistors are explained below.Emitter − It supplies charge carriers. It is highly ... Read More

A microprocessor is digital is a digital circuit which is built using a combination logic functions. The microprocessor package contains an integrated circuit.Integrated CircuitAn integrated circuit is electronic circuit or device that has electronic components on a small semiconductor chip. It has functionality of logic AND or amplifying of a signal. These are mainly two types of circuits: Digital or Analog. Analog ICs handle continuous signals such as audio signals and Digital ICs handle discrete signals such as binary values.Types of Integrated CircuitsThere are different types of integrated circuits based various criteria. Based on intended application, the Integrated Circuit (IC) ... Read More

Let's discuss the Following two applicationsLow order address latchOutput port which is interrupting.Intel 8212 as low-order address latch − Here the low-order address lines and data lines are multiplexed and are available as AD7-0. It is convenient to have the address as many times and the separation of data on the different lines. Let's for an example, if we connect a chip like 2716 in an 8085-based system, the 2716 needs bit address of11 bits in its address pins, and here is separate 8 pins kept for data. Now connecting the AD7-0 pins of 8085 to the LS 8 address ... Read More

We use Intel 8212 in variety of applications. Let us discuss applications of 8212 in Mode 0It acts as buffer which is gatedBus driver which is Bi-directionalFor Interrupting the input portTo supply of eight instructions based on RST.Intel 8212 as gated buffer: A weak logic signal is converted to a strong logic when 8212 works in logic 0. The outputs of 8212 in mode0 is capable of sinking the 15 mA in 0 state, and which proves that a minimum high output voltage of nearly 3.65 V is in the state 1. Intel8212 is always given backup when the input ... Read More

The figure below shows the working of 8212 in mode 1Fig: Working of 8212 in mode 1We use this mode generally when we want 8212 to function as an output port. Here, microprocessor drives DI7-0, and the device at the output receives the information on Do7-0. The clock to the latches is provided in this mode. 8212 latches the information on DI7-0 when the CS makes transition from high to low. The CS signal gets activates when INT* is transferred by the interrupts by the driven data transfer scheme which is always performed when desired. The buffer at the output ... Read More