LPP » INSTRU » VHDLib

EdgeDetection permit to detect the edge of the sin signal.

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

COMPONENT lpp_edge_detection
PORT (
clk : IN STD_LOGIC;
rstn : IN STD_LOGIC;
sin : IN STD_LOGIC;
sout : OUT STD_LOGIC);
END COMPONENT;

|.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 | |

EdgeToLevel ...

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

COMPONENT lpp_edge_to_level
PORT (
clk : IN STD_LOGIC;
rstn : IN STD_LOGIC;
sin : IN STD_LOGIC;
sout : OUT STD_LOGIC);
END COMPONENT;

|.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 | |

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!

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;

|.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 | |

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!

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;

|.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| |