It's the real exchange rate between the dollar and the renminbi that matters most, not the nominal rate.
Cleveland Fed estimates suggest the real rate has fallen somewhat more than the nominal rate, but not a lot: Chinese Inflation and the Renminbi (Owen Humpage and Michael Shenk, Economic Trends, Feb 8):
Exchange rates [the nominal rates, unadjusted for inflation - Ben] are not the only thing that matters for a country’s competitive position. Inflation in China relative to inflation in the United States also affects the relative price of goods. Over the past year, the rate of inflation in China has exceeded the rate of inflation in the United States. The real renminbi–dollar exchange rate combines all three of these variables—the conventional exchange rate, inflation in China, and inflation in the United States—into a convenient metric. Since its peak in August 2006, the dollar has depreciated 9 percent against the renminbi in real terms, compared to 7½ percent in conventional exchange-rate terms.