Registering partition boundaries and reducing combinatorial logic

I have a module dac that is instantiated inside of module registers. The module instance dac drives pins dac_data_bus[11:0] at the top level. I am receiving TimeQuest recommendations to "register the partition boundaries for the path" and "reduce the levels of combinatorial logic."

As I understand it, reduction in the levels of combinatorial logic is to pipeline an operation.

Both dac and registers are driven by the same clock.

Is there a general design method that I can use to register partition boundaries and reduce combinatorial logic? What does this recommendation imply, and how do I fix it?

Here is the TimeQuest output:

Register the partition boundaries for the path from registers:registe...|dac_data_bus[0] (http://about<strong></strong>:blank#) to dac_data_bus[0] [hide details] (http://about<strong></strong>:blank#)

• issue: cross-partition paths (rdb:cross-partition%20paths)

• from: registers:registers|dac:dac|dac_data_bus
• to: dac_data_bus
• timequest analysis: }%20-to%20{dac_data_bus
• partitions that should be merged:

• hard_block:auto_generated_inst -> Top

&#9733;&#9733;&#9733;Reduce the levels of combinational logic for the path from registers:registe...|dac_data_bus[1] (http://about<strong></strong>:blank#) to dac_data_bus[1] [hide details] (http://about<strong></strong>:blank#)

• issue: long combinational path (rdb:long%20combinational%20path)

• from: registers:registers|dac:dac|dac_data_bus
• to: dac_data_bus
• timequest analysis: }%20-to%20{dac_data_bus
• extra levels of combinational logic:

• 2

&#9733;&#9733;&#9733;Reduce the levels of combinational logic for the path from registers:registe...|dac_data_bus[0] (http://about<strong></strong>:blank#) to dac_data_bus[0] [hide details] (http://about<strong></strong>:blank#)

• issue: long combinational path (rdb:long%20combinational%20path)

• from: registers:registers|dac:dac|dac_data_bus
• to: dac_data_bus
• timequest analysis: }%20-to%20{dac_data_bus
• extra levels of combinational logic:

• 2