GATE CSE 1991 | Question: 03,iv

Question

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?

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@Arjun sir, RST here would be Restart Instruction.

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