AR# 45513: ISE Map - ERROR:LIT:693 - Block 'MMCME2_ADV symbol
ISE Map - ERROR:LIT:693 - Block 'MMCME2_ADV symbol
The following error occurs in MAP:
ERROR:LIT:693 - Block 'MMCME2_ADV symbol "physical_group_inst_dl_group/inst_dl_dacif/inst_dl_dacif_core/inst_dac_ddrio _lvds/U0/clkfbout/inst_dl_group/inst_dl_dacif/inst_dl_dacif_core/inst_dac_ddr io_lvds/U0/mmcm_adv_inst"' has its target frequency, FVCO, out of range. Valid FVCO range varies depending on speed grade: 600MHz - 1200MHz(-1), 600MHz - 1440MHz(-2), 600MHz - 1600MHz(-3). The computed FCVO is a function of the input frequency CLKIN1_PERIOD, the division factor DIVCLK_DIVIDE, and the CLKFBOUT_MULT_F attribute (FVCO = 1000*CLKFBOUT_MULT_F/(CLKIN1_PERIOD*DIVCLK_DIVIDE)). The CLKIN_PERIOD attribute may have been set by ngdbuild based on the user specified PERIOD constraint. The current calculated FVCO is 3072.000315 MHz.
The following is from the VHD generated by clocking wizard:
For these given parameters, the calculated FVCO is 1000MHz, which is within the valid range.
Why does the error occur?
Please pay attention to the PERIOD specification for the MMCM's CLKIN1 in UCF.
The value overrides the coregen customization.
In this example, the PERIOD has been set as 307.2MHz, which results in FVCO being over 3000MHz.
You need to modify UCF to match the clock input specification.