At what point does the slave flip-flop in a positive edge triggered JK Master-Slave configuration update its output?

Explanation:

• Master-Slave flip-flop is the cascaded combination of two flip-flops among which the first is designated as master flip-flop while the next is called slave flip-flop.
• The master flip-flop is triggered by the external clock pulse train while the slave is activated at its inversion i.e. if the master is positive edge-triggered, then the slave is negative-edge triggered and vice-versa.
• There will be a change in the output when the state of the slave is affected because the output is taken at the slave.

Working:

The structure of the Master-slave JK flip flop is shown below

Working of Master-Slave flip flop

1) When CLK = High, the Master will be active and the slave will be inactive.

Feedback values don’t change as slave flip flop is inactive. Due to this Master output Toggles only once in one clock pulse.

2) When CLK = low

The latest master outputs are transferred to slave inputs and output is obtained. That is slave output change only once in one clock pulse.

3) Master-Slave JK flip flop is similar to the negative edge triggered flip flop

4) Master-Slave JK flip flop also can be converted to positive edge-triggered as shown