UPGRADE YOUR BROWSER

We have detected your current browser version is not the latest one. Xilinx.com uses the latest web technologies to bring you the best online experience possible. Please upgrade to a Xilinx.com supported browser:Chrome, Firefox, Internet Explorer 11, Safari. Thank you!

AR# 44714

PLL/MMCM DRP - Simulating XAPP878/XAPP879 Produces "Warning: Address DADDR=25"

Description

When simulating the XAPP878 or XAPP879, the following warnings are seen in ModelSim:

# ** Warning: Warning : Address DADDR=25 on the PLL_ADV instance is unsupported. # # Time: 35430 ns Iteration: 2 Instance: /m5_clock_generator_tb/cinst_m5_clock_generator_1/cinst_pll_adv_1

# ** Warning: Warning : Address DADDR=25 on the PLL_ADV instance is unsupported. # # Time: 35570 ns Iteration: 2 Instance: /m5_clock_generator_tb/cinst_m5_clock_generator_1/cinst_pll_adv_1

# ** Warning: Warning : Address DADDR=26 on the PLL_ADV instance is unsupported. # # Time: 35710 ns Iteration: 2 Instance: /m5_clock_generator_tb/cinst_m5_clock_generator_1/cinst_pll_adv_1

# ** Warning: Warning : Address DADDR=26 on the PLL_ADV instance is unsupported. # # Time: 35850 ns Iteration: 2 Instance: /m5_clock_generator_tb/cinst_m5_clock_generator_1/cinst_pll_adv_1

# ** Warning: Warning : Address DADDR=29 on the PLL_ADV instance is unsupported. # # Time: 35990 ns Iteration: 2 Instance: /m5_clock_generator_tb/cinst_m5_clock_generator_1/cinst_pll_adv_1

# ** Warning: Warning : Address DADDR=29 on the PLL_ADV instance is unsupported.

Why is this the case?

Solution

ThePLL and MMCM simulation model does not have all of the DRP registers available, so the simulator does not know how to handle them all and produces the warnings mentioned above. You can safely ignore them and the simulation should be correct. The warnings do not affect overall operation of the simulation.

Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
46790 Spartan-6 FPGA Design Assistant - Troubleshooting Common Clocking Problems N/A N/A
AR# 44714
Date Created 10/28/2011
Last Updated 12/15/2012
Status Active
Type General Article
Devices
  • Spartan-6 LX
  • Spartan-6 LXT
  • Spartan-6Q
  • More
  • Virtex-6 CXT
  • Virtex-6 HXT
  • Virtex-6 LX
  • Virtex-6 LXT
  • Virtex-6 SXT
  • Virtex-6Q
  • Virtex-6QL
  • Less