An 8-bit register in which the tracks of active interrupt requests are kept. Whenever activation of an interrupt request input is done the bit corresponding in IRR register is set to 1. For example, if we activate the IR4 and IR6 inputs bits no 4 and 6 of IRR are set to 1 by making the contents of IRR as 01010000. But the processor is designed only to read the contents of this register but cannot write it to IRR. To read the IRR contents, the processor only has an issue the OCW3 command to the 8259 along with the LS 3 ... Read More
It stores the levels of interrupts to be masked by means of storing the bits of the interrupt level already masked. It differs from other registers by means of only masking of the bits. Other processes remained intact. Let’s take for the assumption that the requests to the IR4 AND IR6 should not be an interrupt to the processor which can be well achieved by setting the bits of IMR to 1. The IMR is written by OCW1 command. The processor here also has the capability to read the contents of the IMRregister. To complete this task, the processor has ... Read More
Also, an 8-bit register which keeps track records of the interrupt requests that are currently being executed. If the request IR6 is currently being served, whose contents of ISR will be 01000000. If by any means the request to IR3 becomes active during the service process of IR6, 8259 sets bit 3 of ISR to 1 and activates the output INT. But bit 6 of ISR always remains set at 1 asIR6 request which is not fully serviced. Hence the contents ofISR become 01001000. The following assumptions stated below helps this to happen.Until 8259 operates in a complete nested mode, without ... Read More
It is also an 8-bit register. The processor here writes to SLR but cannot read. The content of this register here implies a different meaning for Master8259 and Slave 8259. Through Master 8259 information is carried through the IR inputs to which Slave 8259s are connected. If the SLR of Master 8259 is loaded with the value 00001111, then it signifies that:The Slave exists on 8259 namely called as IR0, IR1, IR2 and IR3.No Slave exists on 8259 on this registers IR4, IR5, IR6 and IR7.A Slave 8259 serves information about the IR input of Master 8259 to which the ... Read More
Now in this topic we assume that 8085 is the processor which is used in this microcomputer system. In this slave, no 8259 slaves are used. We should examine properly before 8259 PIC is used in the microcomputer system for performing the interrupt control application. 8259 is configured in such a fantastic way that is found that a variety of information are provided like for IR0 request IV, interrupts like level or edge-triggered, whether 8259s are used single or many, if ICW4 is in need or not and whether for the interrupt requests masking should be done or not. This ... Read More
We have assumed that the processor that the processor used in this microcomputer system is 8085, and the slave which is connected to the input IR4 of Master 8259. The address of the port of 8259 is dependent on the chip and the circuit used. Using ICWs and OCWs the Master 8259 and Slave 8259 have to be programmed individually. But the interesting thing is that the two ICWs, ICW1 and ICW2 have the same meaning distinguishingly Master or Slave. So the discussion about the two ICWs, ICW1, and ICW2 is of no use. So we have not done any ... Read More
Every Java primitive data type has a class dedicated to it. These classes wrap the primitive data type into an object of that class. Therefore, it is known as wrapper classes.The following is the program that displays a Primitive DataType in a Wrapper Object.Example Live Demopublic class Demo { public static void main(String[] args) { Boolean myBoolean = new Boolean(true); boolean val1 = myBoolean.booleanValue(); System.out.println(val1); Character myChar = new Character('a'); char val2 = myChar.charValue(); System.out.println(val2); Short myShort ... Read More
To parse and format a number to decimal, try the following code.Example Live Demopublic class Demo { public static void main( String args[] ) { int val = Integer.parseInt("5"); String str = Integer.toString(val); System.out.println(str); } }Output5In the above program, we have used the Integer.parseInt() and Integer.toString() method to convert a number to decimal.int val = Integer.parseInt("5"); String str = Integer.toString(val);The toString() method above represents a value in string and formats.
Now let us see a program of Intel 8085 Microprocessor. This program will convert ASCII to HEXvalues.Problem StatementWrite 8085 Assembly language program to convert ASCII to Hexadecimal character values. DiscussionWe know that the ASCII of number 00H is 30H (48D), and ASCII of 09H is39H (57D). So all other numbers are in the range 30H to 39H. The ASCII value of 0AH is 41H (65D) and ASCII of 0FH is 46H (70D), so all other alphabets (B, C, D, E, F) are in the range 41H to 46H.Here the logic is simple. We are checking whether the ASCII value is less ... Read More
To parse and format to hexadecimal in Java, we have used the BigInteger class. The java.math.BigInteger class provides operations analogues to all of Java's primitive integer operators and for all relevant methods from java.lang.Math.In the below example, we have taken BigInteger and created an object. With that, some values have been set by us in the arguments as the hexadecimal and the radix i.e. 16 for hexadecimal.BigInteger bi = new BigInteger("2ef", 16);Let us see an example.Example Live Demoimport java.math.*; public class Demo { public static void main( String args[] ) { BigInteger bi = new BigInteger("2ef", 16); ... Read More