VHDL 12 bit BCD counter

Hi, I have a task I am currently working on, written in VHDL. I am to design a three-digit 12-bit incrementor, and write the VHDL code.

I am wondering if this can be done by making a 12-bit input, which then sends the 3 parts (11 downto 8, 7 downto 4, 3 downto 0) to their respective 7-segments, so it can count from 0 to 999, and reset. Does anyone have an illustration or a link where an example of an increment-circuit is displayed?

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