Intel® Quartus® Prime Pro Edition Settings File Reference Manual

ID 683296
Date 4/03/2023
Public

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QII_AUTO_PACKED_REGISTERS

Allows the Compiler to combine a register and a combinational function, or to implement registers using I/O cells, RAM blocks, or DSP blocks instead of logic cells. This option controls how aggressively the Fitter combines registers with other function blocks to reduce the area of the design. Generally, the 'Auto' or 'Sparse Auto' settings should be used for this option. The other options limit the flexibility of the Fitter to combine registers with other function blocks and can result in no fits. When 'Auto', the default setting is selected, the Fitter attempts to achieve the best performance with good area. If necessary, additional logic is combined to reduce the area of the design so that it can fit within the selected device. When this setting is 'Sparse Auto', the Fitter attempts to achieve the highest performance with possibly increased area, but without exceeding the logic capacity of the device. If this option is set to 'Off', the Fitter does not combine registers with other functions. The 'Off' setting severely increases the area of the design and may cause a no fit. If this option is set to 'Sparse', the Fitter combines functions in a way which improves performance for many designs. If this option is set to 'Normal', the Fitter combines functions that are expected to maximize design performance and reduce area. When this option is set to 'Minimize Area', the Fitter aggressively combines unrelated functions to reduce the area required for placing the design, at the expense of performance. When this option is set to 'Minimize Area with Chains', the Fitter even more aggressively combines functions that are part of register cascade chains or can be converted to register cascade chains. If this option is set to any value but 'Off', registers are combined with I/O cells to improve I/O timing (as long as the Optimize IOC Register Placement For Timing option allows it), and with DSP blocks and RAM blocks to reduce the area required for placing the design or to improve timing when possible.

Old Name

AUTO_PACKED_REGISTERS_ARMSTRONG, AUTO_PACKED_REGISTERS_STRATIXII, Auto Packed Registers -- Stratix II/II GX/III Cyclone II/III Arria GX

Type

Enumeration

Values

  • Auto
  • Minimize Area
  • Minimize Area with Chains
  • Normal
  • Off
  • Sparse
  • Sparse Auto

Device Support

  • This setting can be used in projects targeting any Intel FPGA device family.

Notes

This assignment supports Fitter wildcards.

This assignment is included in the Fitter report.

Syntax

set_global_assignment -name QII_AUTO_PACKED_REGISTERS <value>
set_global_assignment -name QII_AUTO_PACKED_REGISTERS -entity <entity name> <value>
set_instance_assignment -name QII_AUTO_PACKED_REGISTERS -to <to> -entity <entity name> <value>

Default Value

Auto