Microcontroller module2

To work the DDRx register an output port set DDRx register 1.

• True

• False

After the execution of following commands

LDI R16, 0X00

OUT DDRB, R1

• Then the PORTB act as a output register

• Then the PORTB act as a input register

• Then the PORTB act as a control register

• Then the PORTB act as a status register

§ To read the data present at the pins, we should read the

• PORT register

• Control register

• PIN register.

• DDR register

To set HIGH a single bit of a given I/O register, we use the following syntax.

• SBIS a, b

• CBI ioReg, bit _ number

• SBIC a, b

• SBI ioReg, bit_num

If we want to mask '4'in the number '45' we do the following command

• LDI R20,0x45

  ANDI R20,0xFF

• LDI R20,0x45

  ANDI R20,0x0F

• LDI R20,0x45

  ANDI R20,0xF0

• LDI R20,0x45

  ORI R20,0xFF

Suppose the content of register R20 is 67, After execution of an instruction the content of register R20 became 76. What may be the instruction?

• LSL R20

• SWAP R20

• ROR R20

• ROL R20

Major reasons for writing programs in C for AVR programing are

• It is easier and less time consuming to write in C than in Assembly.

• C is easier to modify and update.

• You can use code available in function libraries.

• C code is portable to other microcontrollers with little or no modification.

Serializing data is a way of sending a byte of data one bit at a time through a single pin of microcontroller.

• True

• False

The methods to transfer a data serially are:

• Transfer data one bit a time and control the sequence of data and spaces between them.

• Using a serial port. The programmer has very limited control over the sequence of data transfer.

• Using AVR timers

• Using AVR interrupts

I/O bit Manipulation Programming in AVR means

• The I/O ports of ATmega32 are bit-accessible.

• We can access a single bit of I/O port registers.

• For eg: PORTB.0=1; Here we set the 0th bit of PORTB is equal to 1.

• We can use the AND and OR bit wise operations to access a single bit of a given register