Intel® Core™ Ultra Series 3 Processors I/O Registers
| ID | Date | Version | Classification |
|---|---|---|---|
| 872352 | 04/14/2026 | 001 | Public |
USB Audio Offload Link x PCM Stream y Format (UAOL0PCMS4CTL) – Offset f1c0
This register controls the USB Audio Offload Link individual PCM stream operation format.
The total number of stream supported is declared in UAOLxPCMSCAP register, with the stream index ordering of input streams at the lowest, followed by output stream next, followed by bi-directional stream at the highest.
| Bit Range | Default | Access | Field Name and Description |
|---|---|---|---|
| 63:50 | 0h | RO | Reserved (Preserved) (RSVD63) SW must preserve the original value when writing. |
| 49:46 | 8h | RW | Stream Start Offset (SSO) Indicates the xHCI requirement for number of micro frames before the target frame number, to send the initial SC (for capture) or DC (for render). The offset is in units of 125us micro frames required before start of stream, and during restart in case of missed SI. |
| 45 | 0h | RW | Streaming Mode Enable (SME) When set to 1, it enable the audio stream to operate out of the shared clock crossing FIFO in streaming mode. |
| 44 | 0h | RW | FIFO Error Interrupt Enable (FEIE) When set to 1, it allows interrupt event generation when the UAOLxPCMSySTS.FIFOE bit is set. |
| 43 | 0h | RW | Event Interrupt Enable (EIE) When set to 1, it allows interrupt event generation when any of the UAOLxPCMSySTS.EVCx event bits are set. |
| 42:41 | 0h | RW | Audio Sample Size (ASS) Indicate the audio sample size (including the container) of the PCM stream operation. |
| 40 | 0h | RW | Stream Reset (SRST) When set to 1, it synchronously reset the audio stream FIFO and associated SIO Pin Logic. DSP FW / SW should always make sure the UAOLxPCMSySTS.SBUSY = 0 to confirm it has stopped completely before making modification to the stream. |
| 39:33 | 0h | RW | Audio Sample Block Size (ASBS) Indicate the audio sample block size of the PCM stream operation. Unit in number of bytes. |
| 32 | 0h | RW | Stream Enable (SEN) When set to 1, it enables the stream operations. When cleared to 0, it stops the stream operations. DSP FW / SW should always make sure the UAOLxPCMSySTS.SBUSY = 0 to confirm it has stopped completely before making modification to the stream. |
| 31:28 | 0h | RW | Service Interval (SI) Indicate the service interval of the PCM stream operation. |
| 27:17 | 0h | RW | Max Packet Size (MPS) Indicate the SIO credit packet size. Unit in number of bytes. |
| 16:14 | 0h | RW | Packet Multiplier (PM) Indicate how many SIO credit packets are required to deliver the audio payload size per service interval. Value programmed should be CEILING(APS/MPS). |
| 13:0 | 0h | RW | Audio Payload Size (APS) Indicate the audio payload size per service interval. Unit in number of bytes. |