I am trying to create a generated clock whose frequency is a fractional multiplier to its source:
create_generated_clock -name clk_fraction -source [get_pins ex_fpgaex_clock/ex_mmcm_clk_wizard/mmcm_adv_inst/CLKIN1] -multiply_by 6.5 -divide_by 6 [get_pin sex_fpga/ex_mmcm_clk_wizard/mmcm_adv_inst/CLKOUT0]
This constraint causes the following error:
ERROR: [Common 17-161] Invalid option value '6.5' specified for 'multiply_by'.
How can I resolve this error?
Allowable values for the -mutiply_by and -divide_by parameters are integers.
To obtain a fractional output you would need to find the ratio of whole numbers which provide the desired fractional output.
In the case above, you would need to use a -mutiply_by value of 13 and -divide_by value of 12 to obtain the desired output.
For more information, please refer to the help information of the create_generated_clock command or UG835.
AR# 54090 | |
---|---|
日期 | 09/22/2014 |
状态 | Active |
Type | 综合文章 |
Tools |