2.0 KiB
ADR-001: Audio Processor as Audio Domain Master
- Status: Accepted
- Date: 2026-08-01
- Decision Type: Architecture
Context
HubAudio is designed as a modular digital audio platform integrating several audio sources and destinations:
- System Controller streaming subsystem
- Radio Receiver radio receiver
- Bluetooth RX/TX modules
- Digital audio converters
- Analog CODEC/DAC stages
The system requires a central component responsible for:
- digital audio routing
- DSP processing
- timing synchronization
- audio stream management
The Audio Processor has been selected as the central audio processor.
Decision
The Audio Processor is the master component of the HubAudio Audio Domain.
The Audio Processor is responsible for:
- DSP processing
- audio routing
- digital mixing
- signal processing
- audio clock generation
- synchronization of external audio peripherals
The Audio Processor is considered the audio domain master.
The System Controller participates in the Audio Domain as a digital audio source. It does not act as the audio timing master or routing controller. Its role inside the audio domain is equivalent to other digital audio sources. The System Controller has a dual role:
- audio source inside the Audio Domain system supervisor inside the Control Domain
It operates as system supervisor and is responsible for:
- network connectivity
- user interface
- configuration management
- firmware update management
- system control
Consequences
Positive
- Single audio timing reference
- Deterministic audio routing
- Reduced clock synchronization complexity
- Easier debugging and expansion
- Clear separation between control domain and audio domain
Negative
- External audio devices must support slave clock operation
- Clock distribution becomes a critical design element
- Peripheral selection must consider I2S synchronization requirements
Rationale
The Audio Processor is selected not only as a DSP processor but as the central controller of the digital audio domain.
This decision defines the HubAudio architecture.