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IP documentation » History » Revision 20

Revision 19 (Jean-Christophe Pellion, 27/02/2014 05:55 PM) → Revision 20/38 (Jean-Christophe Pellion, 27/02/2014 06:00 PM)

{{>toc}} 

 h1. IP Documentation 

 ---- 

 h2. General Purpose 

 h3. Edge Detection 

 {{collapse(Edge_Detection) 
 EdgeDetection permit to detect the edge of the sin signal. 

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

 <pre><code class="vhdl"> 
   COMPONENT lpp_edge_detection 
     PORT ( 
       clk    : IN    STD_LOGIC; 
       rstn : IN    STD_LOGIC; 
       sin    : IN    STD_LOGIC; 
       sout : OUT STD_LOGIC); 
   END COMPONENT; 
 </code></pre> 

 |_.Signal        |_.Direction      |_.Size    |_.Function                |_. Active     | 
 |clk             |input            |1         |clock domain 1            |rising edge | 
 |rstn            |input            |1         |reset                     |low           | 
 |sin             |input            |1         |signal in                 |              | 
 |sout            |ouput            |1         |signal out                |              | 

 }} 
 {{collapse(Edge_to_level) 
 EdgeToLevel permit to transform the positive edge information into a level information. ... 

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

 <pre><code class="vhdl"> 
   COMPONENT lpp_edge_to_level 
     PORT ( 
       clk    : IN    STD_LOGIC; 
       rstn : IN    STD_LOGIC; 
       sin    : IN    STD_LOGIC; 
       sout : OUT STD_LOGIC); 
   END COMPONENT; 
 </code></pre> 

 |_.Signal        |_.Direction      |_.Size    |_.Function                |_. Active     | 
 |clk             |input            |1         |clock domain 1            |rising edge | 
 |rstn            |input            |1         |reset                     |low           | 
 |sin             |input            |1         |signal in                 |              | 
 |sout            |ouput            |1         |signal out                |              | 

 }} 

 h3. Synchronizer 

 {{collapse(SYNC_FF) 
 Sync_FF permit to synchronize a signal A in the clock domain clk. Normally, A signal should be the output of a FF cloked in an other domain. You shouldtn't have "logic" between the 2 domain. 
 You can configure the number FF use to synchronize (NB_FF_OF_SYNC). 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           | 
 |sin             |input            |1         |signal in               |              | 
 |sout            |ouput            |1         |signal synchronized     |              | 

 }} 

 {{collapse(SYNC_VALID_BIT) 
 SYNC_VALID_BIT permit to synchronize a signal of validity from clock domain clk_in to clock domain clk_out. A validity bit is a signal set "high" only one cycle and zero others. To Synchronize this type of signal, a first stage detect the positive edge, a second synchronizes this signal, and a last transform the edge information to a validity bit. 
 You can configure the FF number of the second stage (NB_FF_OF_SYNC). 

 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         |valid bit clocked in domain 1|              | 
 |sout            |output            |1        |valid bit clocked in domain 2|              | 

 }}