LPP » INSTRU » VHDLib

{{>toc}}

h1. IP Documentation

h2. General Purpose

----

h3. Synchronizer

{{collapse(SYNC_FF)

Sync_FF permit to synchronize a signal A in the clock domain clk. Normally, the A signal must be the output of a FF cloked in an other domain. You shouldtn't have "logic" between the 2 domain.

You can configure the FF number (default 2). This number is depending of the MTBF(Mean Time Between Failure).

p=. !{width: 15%}SYNC_FF.png!

<pre><code class="vhdl">

  COMPONENT SYNC_FF_LPP_JCP

    GENERIC (

      NB_FF_OF_SYNC : INTEGER);

    PORT (

      clk    : IN  STD_LOGIC;

      rstn   : IN  STD_LOGIC;

      A      : IN  STD_LOGIC;

      A_sync : OUT STD_LOGIC);

  END COMPONENT;

</code></pre>

|_.Parameter   |_.Type         |_.Size  |_.Description         |_.Default   |

|NB_FF_OF_SYNC |Integer        |        |Number of FF          |2            |

|\5.|

|_.Signal      |_.Direction    |_.Size  |_.Function            |_. Active   |

|clk           |input          |1       |clock                 |rising edge |

|rstn          |input          |1       |reset                 |low         |

|A             |input          |1       |data in               |            |

|A_sync        |ouput          |1       |data out synchronized |            |

}}

{{collapse(SYNC_VALID_BIT)

SYNC_VALID_BIT permit to synchronize a signal sin from clock domain clk_in in clock domain clk_out. The sin signal is clocked with one FF in clk_in domain and NB_FF_OF_SYNC in clk_out domain.

You can configure the FF number (default 2). This number is depending of the MTBF(Mean Time Between Failure).

p=. !{width: 20%}SYNC_VALID_BIT.png! 

<pre><code class="vhdl">

  COMPONENT SYNC_VALID_BIT_LPP_JCP

    GENERIC (

      NB_FF_OF_SYNC : INTEGER);

    PORT (

      clk_in  : IN  STD_LOGIC;

      clk_out : IN  STD_LOGIC;

      rstn    : IN  STD_LOGIC;

      sin     : IN  STD_LOGIC;

      sout    : OUT STD_LOGIC);

  END COMPONENT;

</code></pre>

|_.Parameter   |_.Type         |_.Size  |_.Description         |_.Default   |

|NB_FF_OF_SYNC |Integer        |        |Number of FF          |2            |

|\5.|

|_.Signal      |_.Direction    |_.Size  |_.Function              |_. Active   |

|clk_in        |input          |1       |clock domain 1          |rising edge |

|clk_out       |input          |1       |clock domain 1          |rising edge |

|rstn          |input          |1       |reset                   |low         |

|sin           |input          |1       |data clocked in domain 1|            |

|A_sync        |ouput          |1       |data clocked in domain 2|            |

}}