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# 20030

LogiCORE SPI-4.2 (POS-PHY L4) - Warnings, errors, or violations occur when simulating a SPI-4.2 design

Description

At the beginning of simulating an SPI-4.2 design, multiple warning messages occur similar to the following: 

 

"There is a 'U'|'X'|'W'|'Z'|'-' in an arithmetic operand" 

"Memory Collision Error on X_RAMB16", 

"X_RAMB16 SETUP Low VIOLATION",  

"X_FF RECOVERY Low VIOLATION",  

"$setup",  

"$hold",  

"$recovery" 

"Warning: /X_FF SETUP Low VIOLATION ON I WITH RESPECT TO CLK;"

Solution

"There is a 'U'|'X'|'W'|'Z'|'-' in an arithmetic operand" 

 

The "'U'|'X'|'W'|'Z'|'-' in an arithmetic operand" error occurs because of uninitialized signals in the testbench.  

 

"Memory Collision Error on X_RAMB16", "X_RAMB16 SETUP Low VIOLATION", "X_FF RECOVERY Low VIOLATION", "$setup", "$hold", "$recovery" 

 

The "Memory Collision" error occurs occasionally because the calendar block is trying to read out values at the same time that you are writing them in; however, this is not a problem because you are only supposed to write to calendar when the core is disabled. 

 

"Warning: /X_FF SETUP Low VIOLATION ON I WITH RESPECT TO CLK;" 

 

These SETUP violations are expected to happen when SPI-4.2 clocks are not ready (SnkClksRdy and SrcClksRdy = 0). When DCMs have not locked or BUFR output has not been defined, timing violations are expected during simulation. 

 

If any of the above warnings, errors, or violations occur before the SPI-4.2 Core is enabled (SnkEn /SrcEn is de-asserted), they are transient and can be safely ignored.

AR# 20030
Date Created 09/03/2007
Last Updated 05/16/2014
Status Archive
Type General Article