Use Clocking Wizard v1.4 core's output to update the CLOCK_MODULE to the above mentioned issues.

Clocking Wizard can be found under 'FPGA Features and Design'/'Clocking' taxonomy in the CORE Generator software.

Aurora 8B10B Core instantiates MMCM component in CLOCK_MODULE. This is present inside <generated core component name>\example_design\clock_module.

The following table shows the Aurora 8B10B core?s clock_module parameters with respect to MMCM attributes:

Clocking Wizard requires input frequency (i.e., CLKIN1_FREQ) and output frequency to generate the MMCM component.

Step1: Input frequency calculation

Input frequency is calculated as (Line rate/20)*1000

Line Rate is Aurora 8B10B core's parameter and refers to c_line_rate parameter in XCO file. This value should be entered as Primary input clock frequency in the Clocking Wizard GUI page 1.

Step2: Output frequency1 calculation

For 2-byte Aurora (i.e. c_lane_width value is 2 in XCO): Output frequency1 is same as Primary input clock frequency.

Output frequency1 = ((Line rate/20)*1000) (in MHz)

For 4-byte Aurora (i.e., c_lane_width value is 4 in XCO): Output frequency1 is half rate of the Primary input clock frequency and can be calculated as follows: Output frequency1 = ((Line rate/20)*1000)/2 (in MHz)

This value should be entered as CLK_OUT1 in the Clocking Wizard GUI page 2.

Step3: Output frequency2 calculation
Output frequency2 is same as Primary input clock frequency calculated in Step1:

This value should be entered as CLK_OUT2 in the Clocking Wizard GUI page 2.

CLK_OUT2 check box must be selected.

If Aurora 8B10B uses two GT REFCLKs (i.e. c_gt_clock_2 is having valid value other than 'None' in XCO),

Then follow Step4 and Step5.

Step4: Output frequency3 calculation

Output frequency3 is same as Output frequency1 calculated in Step2.

This value should be entered as CLK_OUT3 in the Clocking Wizard GUI page 2.

CLK_OUT3 check box must be selected.

Step5: Output frequency4 calculation

Output frequency4 is same as Output frequency2 calculated in Step3.

This value should be entered as CLK_OUT4 in Clocking wizard GUI page2.

CLK_OUT4 check box must be selected.

Clocking Wizard displays all MMCM attribute values in GUI page 4 after the above mentioned steps are followed.

The values displayed in GUI page 4 can be used directly to update Aurora 8B10B core's CLOCK_MODULE or Clocking Wizard core's generated template values can be used to update CLOCK_MODULE.

MMCM uses following simplified formula to calculate VCO frequency range:

VCO Frequency = (CLKFBOUT_MULT_F/DIVCLK_DIVIDE)*CLKIN1_FREQ

Use the above formula and the Virtex-6 FPGA Clocking Resources User Guide (UG362) for reference.