Understanding 8259 Master-Slave Configuration
The 8259 Programmable Interrupt Controller (PIC) is a chip used to manage hardware interrupts. A single 8259 PIC can handle up to 8 distinct interrupt requests (IR lines).
When two 8259 PICs are used with the 8086 microprocessor in a master-slave configuration, one PIC acts as the master and the other as the slave. This setup allows for cascading interrupts.
Calculating Total Available Interrupts
The master 8259 PIC has 8 interrupt request lines. The slave 8259 PIC also has 8 interrupt request lines.
In the master-slave configuration, the total number of interrupts is the sum of interrupts handled directly by the master and those handled by the slave.
The calculation is as follows:
$ \text{Total Interrupts} = (\text{Interrupts on Master}) + (\text{Interrupts on Slave}) $ $ \text{Total Interrupts} = 8 + 8 $ $ \text{Total Interrupts} = 16 $
Therefore, with two 8259s in a master-slave configuration, the 8086 microprocessor can handle a total of 16 interrupts.
This corresponds to Option B.
Important Questions from Microprocessors
- What is the value in AL and CF after the following instruction in 8086 is executed?
MOV AL, 8EH
MOV CL, 02H
SAR AL, CL - What is the content in R1, after the following instructions are executed?
CLR C
MOV A,#4CH
SUBB A,#6EH
JNC NEXT
CPL A
INC A
NEXT: MOV R1, A - When TMOD is 10 H, the timer will operate as ____________.
- The Assembler directive in 8086 which is used to tell the assembler that the names or labels following the directive are in some other assembly module is, ____________.
The magnetic vector potential of an electromagnetic system is given by $ \vec{A}=(y \cos ax) \vec{a_x} + (y+e^x) \vec{a_z}$. The magnitude of the magnetic flux density at the origin is
