What does this AHDL code mean?

[methi]

Hi,

I have some questions regarding the following piece of code...

In the AHDL code, the following variable is declared as below:

HDET_REG : DFF;

Its been used in the code as follows:

HDET_REG.CLK = DIGRESET;
HDET_REG.D = VCC;
HDET.REG.CLRN = !HDET;

My question is that....how does this DFF work

How does CLRN affect the output HDET_REG.Q

Any help is greatly appreciated.

Thank you,

Methi