While Fools should generally take the opinion of Wall Street with a grain of salt, it's not a bad idea to take a closer look at particularly stock-shaking upgrades and downgrades -- just in case their reasoning behind the call makes sense.

What: Shares of Cirrus Logic (CRUS 1.18%) popped about 5% today after the semiconductor company posted strong quarterly results and received a market perform-to-outperform upgrade from Northland Capital Markets.

So what: Along with the upgrade, analyst Tom Sepenzis boosted his price target to $27 (from $22), representing about 31% worth of upside to yesterday's close. So while momentum traders might be turned off by Cirrus' pullback over the past six months, Sepenzis' call could reflect a sense on Wall Street that the concerns surrounding its growth trajectory are becoming overblown.

Now what: Northland raised its 2014 EPS outlook for Cirrus from $1.63 to $1.78. "We are raising our Rating from Market Perform to Outperform and our target price from $22.00 to $27.00 after a strong quarter by the audio component maker," said Sepenzis. "While CRUS still suffers from concentration issues we believe it is pretty firmly entrenched, and is now making small gains outside of its largest customer." When you couple that upbeat outlook with Cirrus' rock-solid balance sheet and reasonable mid-teen forward P/E, it's tough to disagree with Northland's upgrade.