Study Flashcards

Question: Is endianness related to the order in which bytes are stored in memory?

Answer: True

Question: Which processor architecture uses Little Endian order by default?

Intel
Freescale
ARM

Answer: Intel

Question: ______ is the order in which the most-significant byte of a number is stored at the lowest address.

Answer: Big Endian

Question: Why is understanding endianness important in embedded systems?

Answer: Understanding endianness is important in embedded systems to ensure compatibility when transferring data between different systems with different byte order.

Question: In embedded systems, the endianness setting is usually transparent to the programmer.

Answer: True

Question: When does endian ordering matter the most?

When programming in high-level languages
When interacting with hardware
When designing user interfaces

Answer: When interacting with hardware

Question: The width of the ________ determines the addressing range in a computer system.

Answer: address bus

Question: What is the purpose of the stack in a computer system?

Answer: The stack is used for storing local variables and the state of the program before a function call.

Question: In ARM architecture, IO is mapped onto the main memory.

Answer: True

Question: How is memory allocated on the heap in C programming?

Using the malloc() function
Using the free() function
Using global variables

Answer: Using the malloc() function

Question: __________ is used to provide memory dynamically on the heap.

Answer: malloc()

Question: Explain why memory leaks can occur when using dynamic memory allocation.

Answer: Memory leaks can occur when allocated memory is not properly released using the free() function, leading to wasted memory.

Question: The stack in a computer system always follows the FIFO (First In First Out) order.

Answer: False

Question: What segment of memory in embedded systems is typically used for constants and program code?

Heap
Stack
ROM/FLASH

Answer: ROM/FLASH

Question: Can most library functions be called in an interrupt handler?

Answer: False

Question: What should you avoid including in an interrupt handler?

Delay functions
Printing functions
Mathematical functions

Answer: Delay functions

Question: On ARM, R13 is the _________.

Answer: Stack pointer

Question: What is the purpose of the link register (LR) in ARM?

Answer: The link register is used to store the return address for subroutines.

Question: Should you preserve R0 through R3 in ARM?

Answer: False

Question: What is the ARM Procedure Call Standard for passing parameters?

Via registers
Via the stack
Both

Answer: Both

Question: In ARM, the return value of a function is stored in register _________.

Answer: R0

Question: Explain the contract between the calling function and the called function in ARM.

Answer: The calling function expects R0 through R3 to get overwritten, while the called function is expected to preserve R4 and up.

Question: Is it mandatory for the called function to put back any registers it uses in R4 and up?

Answer: True

Question: What makes it easy to push and pop registers in GNU ARM Assembly?

Special instructions
Assembly macros
Standard functions

Answer: Assembly macros

Question: Is it correct that ARM has many more registers than the 6808 processor?

Answer: True

Question: Discuss whether having more registers in ARM is a good thing compared to the 6808 processor.

Answer: Having more registers in ARM can provide benefits such as increased performance and efficiency in handling data and instructions, but it also requires more complex programming and may lead to higher power consumption.