x86-64 architecture

Question 1

how many GPRS

Answer 1

16

Question 2

each gpr holds

Answer 2

64 bits

Question 3

GPRS

Answer 3

rax, rbx, rcx, rdx, rsi, rdi, rbp, rsp, r8-r15

Question 4

accessing portion of GPR

Answer 4

different lettering
- 64 bits –> rax
- lowest 32 bits –> eax
- lowest 16 bits –> ax
- lowest 8 bits –> al

Question 5

what are rFLAGS used for

Answer 5

status and CPU control information; stores status info about instruction that was just executed; updated by CPU and not accessible thru programs

Question 6

carry flag

Answer 6

an rFLAG; used to indicate if previous operation resulted in a carry

Question 7

types of rFLAGS

Answer 7

carry, parity (even # of 1’s) , adjust (binary coded decimals), zero, sign (negative), direction (increment or decrement), overflow

Question 8

all memory addresses hold

Answer 8

one byte (8 bits)

Question 9

memory addresses

Answer 9

fixed length sequence of digits

Question 10

memory location

Answer 10

binary or decimal number

Question 11

little-endian

Answer 11

used for multibyte data types (int, float) last byte of binary representation is stored first

Question 12

big-endian

Answer 12

used for multibyte data types (int, float) ; first byte of binary representation is stored first