Intel® Quartus® Prime Standard Edition用户指南: 设计优化

ID 683230
日期 11/12/2018
Public
文档目录

6.1.3. Perform Register Retiming for Performance

The Perform Register Retiming for Performance option enables the movement of registers across combinational logic, allowing the Intel® Quartus® Prime software to trade off the delay between timing-critical paths and non-critical paths. Register retiming can be done during Intel® Quartus® Prime integrated synthesis or during the Fitter stages of design compilation.
图 49. Reducing Critical Delay by Moving the Register Relative to Combinational Logic

Retiming can create multiple registers at the input of a combinational block from a register at the output of a combinational block. In this case, the new registers have the same clock and clock enable. The asynchronous control signals and power-up level are derived from previous registers to provide equivalent functionality. Retiming can also combine multiple registers at the input of a combinational block to a single register.

图 50. Combining Registers with Register Retiming

To move registers across combinational logic to balance timing, click Assignments > Settings > Compiler Settings > Advanced Settings (Fitter). Specify your preferred option under Optimize for performance (physical synthesis) and Effort level .