Question

Draw master-slave JK FF & write its truth table.

Answer 1

Certainly! The master-slave JK flip-flop is a sequential circuit that uses two JK flip-flops connected in a master-slave configuration to avoid the issues of glitches or incorrect state changes due to asynchronous inputs. Here’s how to draw the circuit and the corresponding truth table.

### Master-Slave JK Flip-Flop

**1. Master Flip-Flop:**
   - The master JK flip-flop is triggered by the clock signal.
   - The J and K inputs are fed into the master flip-flop.
   - The output of the master flip-flop is connected to the input of the slave flip-flop.

**2. Slave Flip-Flop:**
   - The slave JK flip-flop is triggered by the inverted clock signal (i.e., the complement of the clock signal).
   - The output of the master flip-flop is fed into the slave flip-flop.

**Circuit Diagram:**

```
             +--------+       +--------+
    J --------|        |       |        |
              |  M     |       |  S     |
    K --------|  JK    |       |  JK    |
              |  FF    |       |  FF    |
   CLK ------>|        |------>|        |
              |        |       |        |
              +--------+       +--------+
                 |                 |
                 |                 |
                 +--------+--------+
                          |
                          |
                         Q'
                         Q
```

**Explanation:**
- **Master Flip-Flop (M JK FF):** This flip-flop is sensitive to the clock signal. The inputs J and K determine how the state will change when the clock is active.
- **Slave Flip-Flop (S JK FF):** This flip-flop is sensitive to the inverted clock signal. It changes its state based on the output from the master flip-flop.

**Truth Table:**

Here’s the truth table for the master-slave JK flip-flop:

| J | K | CLK | Q(t+1) | Q'(t+1) |
|---|---|-----|--------|---------|
| 0 | 0 | ↑   | Q(t)   | Q'(t)   |
| 0 | 1 | ↑   | 0      | 1       |
| 1 | 0 | ↑   | 1      | 0       |
| 1 | 1 | ↑   | Q'(t)  | Q(t)    |

**Notes:**
- **J** and **K** are the inputs to the flip-flop.
- **CLK** is the clock signal. The arrow (↑) denotes a rising edge of the clock.
- **Q(t+1)** is the output after the clock pulse.
- **Q'(t+1)** is the complement of Q(t+1).
- When J = 0 and K = 0, the flip-flop retains its previous state (no change).
- When J = 0 and K = 1, the flip-flop resets (Q = 0).
- When J = 1 and K = 0, the flip-flop sets (Q = 1).
- When J = 1 and K = 1, the flip-flop toggles its state.

Feel free to ask if you need more details or have any questions!

Answer 2

A Master-Slave JK Flip-Flop is a type of sequential logic circuit used in digital systems. It consists of two JK Flip-Flops connected in series: one as the "master" and one as the "slave." The primary advantage of using a master-slave configuration is to ensure that the output of the flip-flop changes only on the clock's falling edge, which eliminates the problem of race conditions present in a simple JK Flip-Flop.

### Master-Slave JK Flip-Flop Diagram

Here's a basic diagram of a Master-Slave JK Flip-Flop:

```
       _________                 _________
J ----|         |   Q     |-------|         |
     |  Master |--------|  Slave |       Q'
K ----|  JK FF  |        |   JK FF|
     |_________|        |_________|

       CLK (Clock)        CLK (Clock)
```

### Working Description

1. **Master Flip-Flop**: This is the first JK Flip-Flop in the chain. It captures the input values of J and K on the rising edge of the clock signal.
2. **Slave Flip-Flop**: This is the second JK Flip-Flop in the chain. It takes the output of the Master Flip-Flop and changes its state on the falling edge of the clock signal.

### Truth Table

The truth table for the Master-Slave JK Flip-Flop is essentially the same as that for a single JK Flip-Flop but with the timing behavior considered:

| **J** | **K** | **Q (previous)** | **Q (next)** | **Description**                  |
|-------|-------|------------------|--------------|----------------------------------|
| 0     | 0     | 0                | 0            | No change                         |
| 0     | 0     | 1                | 1            | No change                         |
| 0     | 1     | 0                | 0            | Reset (Q = 0)                     |
| 0     | 1     | 1                | 0            | Reset (Q = 0)                     |
| 1     | 0     | 0                | 1            | Set (Q = 1)                       |
| 1     | 0     | 1                | 1            | Set (Q = 1)                       |
| 1     | 1     | 0                | 1            | Toggle (Q = 1)                    |
| 1     | 1     | 1                | 0            | Toggle (Q = 0)                    |

**Notes:**
- **J = 0, K = 0**: The output remains the same (no change).
- **J = 0, K = 1**: The output is reset to 0.
- **J = 1, K = 0**: The output is set to 1.
- **J = 1, K = 1**: The output toggles its state (from 0 to 1 or from 1 to 0).

This table assumes that the clock transitions are clean and that there are no timing issues between the master and slave flip-flops.