Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Synchronous and asynchronous reset


Published on

Synchronous and asynchronous reset in sequential circuits..

Published in: Engineering
  • Be the first to comment

Synchronous and asynchronous reset

  2. 2. WHY RESET IS USED..?  Reset is used to initialize the hardware design of a system and to make system to known state from unknown state. Ex…RESET SIGNAL 12/11/2014 ANINDRA 2
  3. 3. TYPES OF RESETS…. 12/11/2014 ANINDRA 3  Reset is of two types :- 1. Synchronous reset :-- a synchronous reset will reset the circuit at active edge of clock .
  4. 4. ADVANTAGES OF SYNCHRONOUS RESET….  Gives a completely synchronous circuit  Provides filtering for the reset signal, So circuit will not be affected by glitches.  Will meet reset recovery time, as the deassertion will happen within 1 clock cycle 12/11/2014 ANINDRA 4
  5. 5. DISADVANTAGES…  Reset needs to be stretched, if it is not long enough to be seen at the active clock edge.  Requires presence of clock to reset the circuit.  Asynchronous reset may be required if there are 12/11/2014 ANINDRA 5 internal tri state buffers.
  6. 6. DISADVANTAGES…. 12/11/2014 ANINDRA 6  It is slow.  Synthesis will not be able to easily differentiate reset from other signals. So this has to be taken care while doing synthesis. Otherwise it may lead to timing issues.  If there are gated clocks for power saving, this type of reset won’t be suitable.
  7. 7. ASYNCHRONOUS RESET…. 2. Asynchronous reset :-- asynchronous reset will reset the circuit asynchronously i.e no matter with the clock. 12/11/2014 ANINDRA 7
  8. 8. ASYNCHRONOUS RESET ADVANTAGES ….  Reset gets the highest priority. 12/11/2014 ANINDRA 8  It is fast.  Does not require presence of clock to reset the circuit.
  9. 9. DIADVANTAGES…  Reset line is sensitive to glitches.  May have metastability issues 12/11/2014 ANINDRA 9
  10. 10. THANK YOU 12/11/2014 10 ANINDRA