CH4 Review Questions

Question 1

There are a total of _____ ports in the ATmega32.

Answer 1

4

Question 2

True or False.

All of the ATmega32 ports have 8 pins.

Answer 2

True

Question 3

True or False.

Upon power-up, the I/O pins are configured as output ports.

Answer 3

False

Question 4

Code a simple program to send 0x99 to Port B and Port C.

Answer 4

LDI R16, 0xFF

OUT DDRB, R16

OUT DDRC, R16

LDI R16, 0x99

OUT PORTB, R16

OUT PORTC, R16

Question 5

To make Port B an output port, we must place ______ in register ______.

Answer 5

$FF, DDRB

Question 6

To make Port B an input port, we must place _____ in register ______.

Answer 6

$00, DDRB

Question 7

True or False.

We use a PORTx register to send data out to AVR pins.

Answer 7

True

Question 8

True or False.

We use PINx to bring data into the CPU from AVR pins.

Answer 8

True

Question 9

True or False.

The instruction “SBI PORTB, 1” makes pin PB1 HIGH while leaving other pins of PORTB unchanged, if bit 1 of the DDR bits is configured for output.

Answer 9

True.

Question 10

Show one way to toggle the pin PB7 continuously using AVR instructions.

Answer 10

CBI DDRB, 7

H1: SBI PORTB, 7

CBI PORTB, 7

RJMP H1

Question 11

Write instructions to get the status of PB2 and put it on PB0.

Answer 11

CBI DDRB, 2

SBI DDRB, 0

AGAIN: SBIS PINB, 2

RJMP OVER

SBI PORTB, 0

RJMP AGAIN

OVER: CBI PORTB, 0

RJMP AGAIN

Question 12

Write instructions to toggle both bits of PD7 and PD0 continuously.

Answer 12

SBI DDRD, 0

SBI DDRD, 7

H2: SBI PORTD, 0

SBI PORTD, 7

CBI PORTD, 0

CBI PORTD, 7

RJMP H2