We just switched from an K20 to a K22 microcontroller and noticed the PE eDMA component initialization had started hard-faulting when trying to set a mysterious new DMA_EARS register. Perplexed, we looked up the register in the K22 datasheet and found it cryptically described as "Enable Asynchronous Request in Stop Register" in the reference manual. We could not find any further description of its function or even what this "stop register" was. It is also notably missing from the K20 manual.
Commenting out the line in DMA_Init() which initialized the register value prevented the hard fault and allowed the DMA module to function as it did on the K20.
Is it possible that DMA_EARS was deprecated (or never present) and that the datasheet and register map are outdated? The only other valid reference to this register I can find on the web at large is in this header from mbed which claims it is deprecated: