Question

how many types of registers are? 4 ○ 5 ○ 2 ○ 3 ○ 6 ○ serial in/parallel out, 4 - bit shift register initially contains all 1s. the data nibble 0111 is waiting to enter. after four clock pulses, the register contains ____ 0000 ○ 1111 ○ 0111 ○ 1000 ○ none of the above ○ an asynchronous 4 - bit binary down counter changes from count 2 to count 3. how many transitional states are required? 1 ○ 2 ○ 15 ○ 16 ○ none ○

Explanation:

Step1: Analyze types of registers

There are 6 main types of registers: accumulator, data register, address register, program counter, instruction register, and flag register. So the answer to "How many types of registers are?" is 6.

Step2: Analyze shift - register operation

In a serial - in/parallel - out shift register, with each clock pulse, the data shifts in. Initially, the register has all 1s. The data nibble 0111 is waiting to enter. After four clock pulses, the data 0111 will be shifted in completely. So the register contains 0111.

Step3: Analyze asynchronous counter state - change

An asynchronous 4 - bit binary down - counter: The binary representation of 2 is 0010 and of 3 is 0011. In an asynchronous counter, each flip - flop changes state independently. To go from 0010 to 0011, only 1 bit (the least significant bit) needs to change, so 1 transitional state is required.

Answer:

1. 6
2. 0111
3. 1