Hi, Takashima,
Regarding your question, I have googled with the key words "HE-AAC", this is the explanation:
High-Efficiency Advanced Audio Coding - Wikipedia
The HE-AAC is audio coding format, user can recover the HE-AAC data to PCM stream and output the PCM stream to codec via I2S data format via SAI interface. User can get the data with HE-AAC format via USB, SAI input module...
I think the codec device is an ADC or DAC, it can not receive HE-AAC data format directly usually, the Codec can only receive PCM data format with I2S protocol. The processor should recover to PCM from HE-AAC data stream.
the K64 and K22 have SAI interface, it can receive/transmit data via I2S protocol.
Hope it can help you
BR
Xiangjun Rong