Abstract: A compressed over pulse-code modulation (PCM) (CoP) format (e.g., for data transfer between a Bluetooth component and an audio digital signal processor (ADSP) component) may be modified to transport additional metadata (e.g., sideband data). Sideband data may be transported to convey parameter control information (e.g., control information for codec parameter control interfaces, such as information for quality mode changes), in band data (e.g., data specific parameters, such as timestamps for playback timing control and synchronization purposes), etc. Sideband data may be transported (e.g., communicated) over an interface between a Bluetooth component and an ADSP component while an applications processor is operating in a low power state or sleep mode. According to some aspects, the modified CoP format (e.g., a sideband packet) may include a sideband identification (ID) field and a sideband data payload (e.g., where the sideband ID field indicates the structure of a corresponding sideband data payload).