EN0-001 Exam Dumps - ARM Accredited Engineer
When using an Operating System, which instruction is used by user code to request a service from the kernel?
In a Cortex-A9 processor, when the Memory Management Unit (MMU) is disabled, which of the following statements is TRUE? (VA is the virtual address and PA is the physical address)
Before execution:
R0=0xFFFFFFFF
R1 = ?
EOR R0, R0, R1
If R0=0x00000000 after executing the EOR instruction above, what was the value in R1 before the instruction executed?
The following pair of functions implement a simple mutex spinlock which might be used to protect a critical code section in a multi-threaded application. The address of the lock variable is in r0.
In order to minimize power while waiting for the lock to be available. SEV and WFE instructions can be used to place the processor in a low power state while waiting for the lock to become available. At which points should these instructions be placed?
A simple method of measuring the performance of an application is to record the execution time using the clock on the wall or a wristwatch.
When is this method INAPPROPRIATE?
The Memory Protection Unit (MPU) of Cortex-R4 performs which of the following tasks?
An interrupt handler contains the following instruction sequence at the end. The purpose of these instructions is to clear the interrupt request in the interrupt controller and then safely re-enable interrupts.
STR r0, [r1] ; write to interrupt controller register to clear interrupt request
CPSIE i ; re-enable IRQ interrupts
Which of the following instructions should be placed at position
Which of the following pairs of statements about the difference between a Memory Management Unit (MMU) and a Memory Protection Unit (MPU) is correct?