Microprocessor Articles - Page 12 of 42

Intel 8085 consists of a RESET_IN* pin which is an active low input pin. We RESET 8085 by placing a logic 0 on this pin at least for 0.5μs, after that the power is supplied to Vcc pin of 8085. Moreover, in practice we place the RESET_IN* in logic 0 state for a few milliseconds. A typical reset circuit which we use in ALS 8085 kit, is shown in the following Fig.The moment when the power supply is switched on, the Vcc pin gets +5V power here the RESET_IN* pin stays in logic 0 state for a time dependency on the ... Read More

Status check data transfer process is a much more complex process than simple data transfer. We use this method is used when there is lack of accurate knowledge of the Input Output device consisting of the timing characteristics. Status information is received by the processor regarding the readiness of the Input Output device for performing the data transfer. Generally, the processor is involved in the checking of the loop for the device to get ready. The device releases from the loop when the device is ready for use for the execution of the IN or OUT instruction which depends on ... Read More

At the time of executing one 8085 program, interruption can be done in the mid-way by the virtue of the program by an Input Output device. Interruption can be done by the method according to which the processor works, since it wants urgent communication with the processor. The data transfer schemes always want for sending information to the processor, rather receiving information from the 8085 processor. It is so because sending and receiving information in the entire 8085 data transfer scheme process plays a vital role for executing the entire program rather process.The communication is not done directly with the ... Read More

In Memory Mapped Input Output −We allocate a memory address to an Input-Output device.Any instructions related to memory can be accessed by this Input-Output device.The Input-Output device data are also given to the Arithmetic Logical Unit.Input-Output Mapped Input Output −We give an Input-Output address to an Input-Output device.Only IN and OUT instructions are accessed by such devices.The ALU operations are not directly applicable to such Input-Output data.So as a summary we can mention that −I/O is any general-purpose port used by processor/controller to handle peripherals connected to it.I/O mapped I/Os have a separate address space from the memory. So, total ... Read More

In this program we will see how to transfer a 4-byte block from one location to another location.Problem StatementWrite 8086 Assembly language program to transfer a four-byte block from one memory section to another memory section. The numbers are stored at memory offset 500 – 503.DiscussionHere we are initially setting up the source index register with the source of data blocks, then set the destination index register to store into another block. Then set the Data segment register and Extra Segment register to 0000H. By using MOVSB instruction, the entire block is transferred from one location to another. As the ... Read More

In this program we will see how to sort array elements in ascending order.Problem StatementWrite 8086 Assembly language program to sort the elements in a given array, which is starts from memory offset 501. The size of the series is stored at memory offset 500.DiscussionHere we are sorting the number in bubble sorting technique. In this sorting technique there will be n passes for n different numbers. In ith pass the ith largest element will be placed at the end. This is comparison based sort. We taking two consecutive numbers, compare them, and then swap them if the numbers are ... Read More

In this program we will see how to find the minimum number in a given array.Problem StatementWrite 8086 Assembly language program to find the minimum number in a given array, which is starts from memory offset 501. The size of the series is stored at memory offset 500. Store the minimum number at memory offset 600.DiscussionAt first we are taking the size of the array from memory offset 500. Then using that size, we are initializing the counter to read and check all the numbers. We are taking the first number into AL, then check each number and compare it ... Read More

In this program we will see how to find the largest number in a given array.Problem StatementWrite 8086 Assembly language program to find the largest number in a given array, which is starts from memory offset 501. The size of the series is stored at memory offset 500. Store the largest number at memory offset 600.DiscussionAt first we are taking the size of the array from memory offset 500. Then using that size, we are initializing the counter to read and check all the numbers. We are taking the first number into AL, then check each number and compare it ... Read More

In this program we will see how to find the equivalent BCD number from an ASCII value.Problem StatementWrite 8086 Assembly language program to find the equivalent BCD number from an ASCII value. The number is stored at memory location 2050 and store the result at memory location 3050.DiscussionThis program can change ASCII value of a number to its BCD (Decimal) form. The ASCII values of the numbers are like below:ASCII (in Hex)30313233343536373839BCD00010203040506070809 From this table we can easily find that the last nibble of the ASCII value is actually the BCD equivalent. So to take the last nibble we have masked ... Read More

In this program we will see how to find the equivalent hexadecimal number from a BCD number.Problem StatementWrite 8086 Assembly language program to find the equivalent hexadecimal number from a BCD number. The number is stored at memory offset 500 and store the result at memory offset 600.DiscussionTo convert BCD to hexadecimal at first we have to cut the BCD digits. The most significant digit will be multiplied with 0AH (10D), and then least significant digit will be added with the result of multiplication. Thus the BCD will be converted to its equivalent hexadecimal form.InputAddressData……50059…… Flow Diagram ProgramOutputAddressData……6003B……