ARM ARM Certifications EN0-001 Questions & Answers

• Question 171:

  Which of the following properties is a required characteristic of a Symmetric Multiprocessing (SMP) system?

  A. All processors have the same view of memory

  B. An even number of processors is included

  C. All processors run in the same power state

  D. All processors switch between operating system tasks in lock-step

  Correct Answer: A

• Question 172:

  Which of the following techniques can be used to obtain a precise count of clock cycles when profiling software over an arbitrarily long period of time using the Performance Monitoring Unit?

  A. A dedicated real-time clock to provide the total cycle count

  B. Use of the divide-by 64 counting option to avoid an overflow of the cycle counter

  C. Use of the overflow interrupts, to extend the range of the built-in 32-bit counter

  D. Modification of the application software being profiled, to insert timestamps at regular intervals

  Correct Answer: C

• Question 173:

  Which of the following is preserved in dormant mode?

  A. Core register contents

  B. CP15 (system) register settings

  C. Debug state

  D. Cache contents

  Correct Answer: D

• Question 174:

  In general, when programming in C, stack accesses will be reduced by:

  A. Disabling inlining.

  B. Never passing more than four parameters in function calls.

  C. Declaring automatic variables as "packed".

  D. Configuring the compiler to optimize for space.

  Correct Answer: B

• Question 175:

  Consider the following instruction sequence: STR r0, [r2] ; instruction A DSB ADD r0, r1, r2 ; instruction B LDR r3, [r4] ; instruction C

  SUB r5, r6, #3 ; instruction D

  At what point will execution pause until the STR access is complete?

  A. After instruction A and before the DSB

  B. After the DSB and before instruction B

  C. After instruction B and before instruction C

  D. After instruction C and before instruction D

  Correct Answer: B

• Question 176:

  What is an "Entry point" in an application?

  A. A place where execution can start

  B. The location of the main () function

  C. The lowest address contained in a program image

  D. A location where the linker can store additional information

  Correct Answer: A

• Question 177:

  In an ARMv7-A processor, with which level of the memory system is the Memory Management Unit (MMU) associated?

  A. Level 1

  B. Level 2

  C. Level 3

  D. Level 4

  Correct Answer: A

• Question 178:

  An application contains three calls to an external function, foobar(), which is defined in a shared (or dynamic) library. How many copies of foobar() will the linker place in the application image?

  (Ignore linker inlining)

  A. None

  B. Always one

  C. Always three

  D. One or more depending on optimization level

  Correct Answer: A

• Question 179:

  In an MPCore system, when one core is waiting for resources to be released, what instruction could be used to reduce that core's power consumption?

  A. WFE

  B. PLD

  C. NOP

  D. DSB

  Correct Answer: A

• Question 180:

  According to the AAPCS (with soft floating point linkage), when the caller "func" calls sprintf, where is the

  value of the parameter "x" placed?

  #include

  void func(double x, int i , char *buffer)

  {

  sprintf(buffer, "pass %d: value = %f\n", i, x); }

  A. Split between register R3 and 4 bytes on the stack

  B. Split between registers R3 and R4

  C. 8 bytes on the stack

  D. VFP Register D0

  Correct Answer: C