Apple (AAPL) -1.2% after Cirrus Logic (CRUS), which gets over half of its revenue from the company, issues a revenue warning for the March and June quarters (FQ4 and FQ1). Though Cirrus' FQ4 revenue forecast of $206.9M is only a little below a $210.2M consensus, its FQ1 forecast of $150M-$170M is well below a $195.2M consensus. The audio codec chipmaker also says it will take a $23.3M write-down, $20.7M of which is due to "a decreased forecast for a high volume product" as a customer (quite possibly Apple) migrates to a new component (could be a sign of a new iPhone). SWKS -2.2%. QCOM -0.9%.