SRFLIPFLOP
==========

SR flip-flop



Block Screenshot
~~~~~~~~~~~~~~~~





Contents
~~~~~~~~


+ `SR flip-flop`_
  +

    + `Palette`_
    + `Description`_
    + `Data types`_
    + `Dialog box`_
    + `Default properties`_
    + `Example`_
    + `Interfacing function`_
    + `See also`_





Palette
~~~~~~~


+ `Integer palette`_




Description
~~~~~~~~~~~

This block describes the simplest and the most fundamental latch the
SR flip flop. The output **Q** depends of the state of the inputs
**S** and **R**. The output **!Q** is the logical negation of **Q**


+ If **S** (Set) is pulsed high while **R** is held low, then the
  **Q** output is forced high, and stays high when **S** returns low.
+ if **R** (Reset) is pulsed high while **S** is held low, then the
  **Q** output is forced low, and stays low when **R** returns low.
+ When **S** and **R** are low, **Q(t)** takes the value of the
  previous output state **Q(t-1)**.
+ When **S** and **R** are both high, both **Q** and **!Q** take the
  low or high values; the state is unstable. Practically this case is
  forbidden.


The user can set the initial output state with **Initial Value**
parameter.

This block is almost used as a memory

The truth table of this block is:


Hold Reset Set Forbidden state
where * `U`* stands for "Unknown".



Data types
~~~~~~~~~~

The block supports the following types :


+ Inputs:

    + **R**: scalar. Scilab's int8 data type only.
    + **S**: scalar. Scilab's int8 data type only.
  A positive input is considered as logical 1, a negative or a null
  input as logical 0.
+ Outputs: scalar. Scilab's int8 data type.




Dialog box
~~~~~~~~~~






+ **Initial Value** Initial Value of the state Q. It must be int8 data
  type. Properties : Type 'vec' of size 1.




Default properties
~~~~~~~~~~~~~~~~~~


+ **always active:** no
+ **direct-feedthrough:** yes
+ **zero-crossing:** no
+ **mode:** no
+ **regular inputs:** **- port 1 : size [1,1] / type 5** **- port 2 :
  size [1,1] / type 5**
+ **regular outputs:** **- port 1 : size [1,1] / type 5** **- port 2 :
  size [1,1] / type 5**
+ **number/sizes of activation inputs:** 0
+ **number/sizes of activation outputs:** 0
+ **continuous-time state:** no
+ **discrete-time state:** no
+ **object discrete-time state:** no
+ **name of computational function:** csuper




Example
~~~~~~~

The following example presents a typical anti-bouncing application of
the SR flipflop. The output graph shows the memory effect of the
flipflop. `Open this example in Xcos`_



Interfacing function
~~~~~~~~~~~~~~~~~~~~


+ `SCI/modules/scicos_blocks/macros/IntegerOp/SRFLIPFLOP.sci`_




See also
~~~~~~~~


+ `DLATCH`_ D latch flip-flop
+ `DFLIPFLOP`_ D flip-flop
+ `JKFLIPFLOP`_ JK flip-flop


.. _JKFLIPFLOP: JKFLIPFLOP.html
.. _Example: SRFLIPFLOP.html#Example_SRFLIPFLOP
.. _DLATCH: DLATCH.html
.. _SR flip-flop: SRFLIPFLOP.html
.. _Data types: BITCLEAR.html#Data_Type_BITCLEAR
.. _Default properties: SRFLIPFLOP.html#Defaultproperties_SRFLIPFLOP
.. _SCI/modules/scicos_blocks/macros/IntegerOp/SRFLIPFLOP.sci: nullscilab.scinotes/scicos_blocks/macros/IntegerOp/SRFLIPFLOP.sci
.. _Palette: SRFLIPFLOP.html#Palette_SRFLIPFLOP
.. _DFLIPFLOP: DFLIPFLOP.html
.. _Interfacing function: SRFLIPFLOP.html#Interfacingfunction_SRFLIPFLOP
.. _Dialog box: SRFLIPFLOP.html#Dialogbox_SRFLIPFLOP
.. _Description: SRFLIPFLOP.html#Description_SRFLIPFLOP
.. _Open this example in Xcos: nullscilab.xcos/xcos/examples/integer_pal/en_US/SRFLIPFLOP_en_US.xcos
.. _See also: SRFLIPFLOP.html#Seealso_SRFLIPFLOP
.. _Integer palette: Integer_pal.html