Exam 1

Question 1

How wide is Flash ROM?

Answer 1

16 Bits

Question 2

How Wide is RAM?

Answer 2

8 bits

Question 3

How wide is OPCODE?

Answer 3

16 bits

Question 4

How many address lines are needed to address RAM which has 64k

Answer 4

16 lines

Question 5

How many address lines are needed to address Program Flash ROM which has 64K

Answer 5

15 lines

Question 6

BRCS

Answer 6

Branch if carry set

Question 7

True or False: The target of a BRNE can be anywhere in the 4M word address space.

Answer 7

False, all conditional branches are short jumps (2 byte instructions) and must be within 64 bytes of PC

Question 8

Size of long jmp

Answer 8

4 bytes

Question 9

Size of rjmp

Answer 9

2 bytes

Question 10

Size of ijmp

Answer 10

Stuffed into Z registers 2 bytes

Question 11

True or False:The target address of a BRNE is forward if the relative address of the opcode IS negative.

Answer 11

Negative means backwards

Positive means forwards

Question 12

How to find target location of Branching statement using the OPCODE

Answer 12

Target Location = PC + Bits 3-9 + 1

If negative number take 2s complement and then continue

Question 13

CALL is a ____ byte instruction

Answer 13

4 byte

Question 14

RCALL is a ____ byte instruction

Answer 14

2 byte

Question 15

True or False: The RCALL target address can be anywhere in the 4M (word) address space?

Answer 15

False

Question 16

True or False: The CALL target address can be anywhere in the 4M address space

Answer 16

True

Question 17

When CALL is executed, how many locations of the Stack are used?

Answer 17

2

Question 18

In AVR, which address is pushed into the Stack when the CALL instruction is executed?

Answer 18

The address of the next instruction immediately after the CALL instruction

Question 19

How to initialize Stack Pointer

Answer 19

LDI R17,HIGH(RAMEND)
OUT SPH,R17
LDI R17,LOW(RAMEND)
OUT SPH,R17

Question 20

How to set all pins for PortB

Answer 20

LDI R16,$FF
OUT DDRA,R16
OUT PORTB,R16
CBI DDRB, 0