GATE1991-03,iv

Question

Choose the correct alternatives (more than one may be correct) and write the corresponding letters only:

The TRAP interrupts mechanism of the $8085$ microprocessor:

(a). executes an $RST$ by hardware

(b). executes an instruction supplied by an external device through the $INTA$ signal

(c). executes an instruction from memory location $20H$

(d). executes a NOP

(e). none of the above

Answer 1

Answer would be (e) None of the above. Because TRAP cuts input voltage to reset the processor in the event of loss of power.

(a). executes an RST by hardware : This will not be answer, Because RST is different Interrupt than TRAP.

(b). executes an instruction supplied by an external device through the INTA signal : Again there is a different interrupt pin called INTA. Hence It is not at all related to TRAP.

(c). executes an instruction from memory location 20H : RST 4 executes the memory address 0020H. Its not TRAP.

(d). executes a NOP : This can not be the answer.

Read this for more details : http://scanftree.com/microprocessor/Interrupts-In-8085

Comments

@Arjun Sir and @Kathleen please have a look in this. 

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what is RST here?

Answer 2

answer should be A. TRAP is also known as RST 4.5 and it executes an RST by hardware.

see diagram on page 2

http://uotechnology.edu.iq/dep-laserandoptoelec-eng/branch/lectures/microprocessor/26.pdf