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AR# 67309

MicroBlaze MCS - MCS clock can only be set to 100MHz


I have a simple Vivado IP Integrator design using the MicroBlaze MCS IP from the IP catalog. However, I cannot set the MCS clock to anything other than 100Mhz, even if the source clock is different.

How can this issue be addressed?


When changing clock frequency for a MicroBlaze MCS v3.0 instantiated in a Vivado IP Integrator Block Design in Vivado 2016.1 or 2016.2, the following commands must be entered in the Vivado Tcl Console.

This is necessary avoid a propagation error for the clock frequency:

set_property CONFIG.FREQ_HZ.VALUE_SRC PROPAGATED [get_bd_pins <microblaze_mcs_instance>/Clk]

validate_bd_design -quiet

set_property CONFIG.FREQ_HZ.VALUE_SRC PROPAGATED [get_bd_pins <microblaze_mcs_instance>/Clk]


 Here <microblaze_mcs_instance> should be replaced with the actual instance name in the Block Design.

Also ensure that the "Input Clock Frequency (MHz)" in the MCS tab of the MicroBlaze MCS customization dialog is set to "Auto".

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Master Answer Records

AR# 67309
Date Created 06/01/2016
Last Updated 06/07/2016
Status Active
Type General Article
  • Vivado Design Suite - 2016.2
  • Vivado Design Suite - 2016.1
  • MicroBlaze Micro Controller System (MCS)