what does ffgen in design vision mean?

[sudheerprasad]

hi,
when im synthesizing my code im getting a warning "Target library contains no replacement for register 'shiftmem_douta_reg[3]' (**FFGEN**)", shiftmem_douta_reg is a variable defined as a reg in the code,all internal variables defined as reg are being replaced by "ffgen".my library contains only a posedge dff,do i need any xtra cell to avoid ffgen,or is there any other way?

 

[ic_qiand]

hi!

maybe, you've "set_dont_use" some cells in your library, and synthesis tools can find the cells.