can someon help me with these 1. suppose that a JSR instruction in LC3 assembles

Question

can someon help me with these

1. suppose that a JSR instruction in LC3 assembles as x4816 and the instruction is located at x3306 in memory. what is the effective address of the corresponding subroutine? justify.

2. how many trap service routines may be implemented in LC3. Why?

3. can a JMP R7 instruction be executed in lieu of a RET instruction in order to return from a TRAP? Explain.

4. How many accesses to memory are made during the excecution phase of a TRAP instruction? assume that the TRAP instructions is already in the instruction register

Explanation / Answer

2. how many trap service routines may be implemented in LC3. Why?

Answer:

. 256 trap routines can be implemented in the LC-3

Explanation:

There are 256 TRAP vector locations (located at x0 to xFF in memory); hence, in LC-3,

we can have as many as 256 TRAP service routines.

4. How many accesses to memory are made during the excecution phase of a TRAP instruction? assume that the TRAP instructions is already in the instruction register

Answer:

2 memory accesses are made during TRAP instruction

1st access:- instruction in fetch

2nd access:- trap vector table to get address of TRAP service routine

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