VHDL Practice Test 7

1. Which of the following is used to extract information of non-array types?

Non vector type

Scalar type

Vector type

Array type

2. The parameter of a procedure can have any of the three modes.

True

False

3. For which of the following declarations, the value returned by ‘ASCENDING attribute will be true?

TYPE array_1 IS ARRAY (0 TO 31) OF BIT;
TYPE array_2 IS ARRAY (15 DOWNTO 0) OF BOOLEAN;

Neither for array_1 nor for array_2

For both array_1 and array_2

For array_2 only

For array_1 only

4. What is the type of value returned by the s’DELAYED(time) attribute?

TIME

BOOLEAN

INTEGER

Same as signal s

5. Refer to the statement given below, it is used for detecting _________

IF (clk’EVENT and clk = ‘0’)

Rising edge of the clock signal

Clock signal frequency

Time period of clock signal

Falling edge of the clock signal

6. What kind of information is provided by the value block attributes?

About the inputs used in block

About the modeling of block

About the block name

About the architecture name

7. What is the basic syntax to write an attribute?

Attribute_name’ Object_name (parameter)

Object_name’ attribute_name (parameter)

Object_name : Attribute_name (parameter)

Attribute_name : Object_name (parameter)

8. What will be the value of array16’RANGE and array16’REVERSE_RANGE, if the array16 is an object defined as below?

TYPE array16 IS ARRAY(15 DOWNTO 0) OF BIT

0 TO 15, 15 DOWNTO 0

15 DOWNTO 0, 15 DOWNTO 0

0 TO 15, 0 TO 15

15 DOWNTO 0, 0 TO 15

9. Identify the value of variable x from the lines given below.

SUBTYPE delay_time IS TIME RANGE 10 ns to 50 ns;
VARIABLE x := delay_time'BASE

10 ns

time

50 ns

10. Which of the following describes the function of ‘PRED(value)?

To return the position of value next to the value passed in argument

To return the value previous to the value passed in the argument

To return the position of value next to the value passed in argument

To return the value next to the value passed in argument of the attribute