diff options
Diffstat (limited to 'examples/host')
| -rw-r--r-- | examples/host/audio_host/README.md | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/examples/host/audio_host/README.md b/examples/host/audio_host/README.md index 88c948ccd..bbb3a7684 100644 --- a/examples/host/audio_host/README.md +++ b/examples/host/audio_host/README.md @@ -98,10 +98,10 @@ Edit `src/tusb_config.h` to modify: - `CFG_TUH_AUDIO_MAX`: Maximum number of audio devices supported - `CFG_TUH_AUDIO_EPIN_BUFSIZE`: Maximum size of one capture transfer the driver submits (configurations needing a larger per-poll-interval packet are rejected) - `CFG_TUH_AUDIO_EPOUT_BUFSIZE`: Maximum size of one playback transfer the driver submits -- `CFG_TUH_AUDIO_STREAM_BUFSIZE`: Per-stream FIFO depth in bytes (default 1024, i.e. four 256 B packets) +- `CFG_TUH_AUDIO_STREAM_BUFSIZE`: Per-stream FIFO depth in bytes (default 1024, i.e. four 256 B packets); capture overwrites the oldest frames when full ## Notes - While a stream is running, the driver keeps one isochronous transfer in flight and re-submits on completion, so transfers follow the endpoint's `bInterval`. `tuh_audio_capture_cb()` / `tuh_audio_playback_cb()` report each completed transfer; `tuh_audio_err_cb()` reports failures. The example restarts the failed stream automatically 100 ms after the error callback. -- `tuh_audio_read()` / `tuh_audio_write()` are non-blocking FIFO operations: they return the number of whole frames actually queued/read (0 when the FIFO is empty/full or the stream is not running), and `tuh_audio_read_available()` / `tuh_audio_write_available()` report the FIFO occupancy in frames. -- Isochronous transfers require the host to poll `tuh_task()` continuously; the capture FIFO absorbs short scheduling gaps, but frames are dropped when it overflows. +- `tuh_audio_read()` / `tuh_audio_write()` are non-blocking FIFO operations: they return the number of whole frames actually queued/read (0 when the FIFO is empty/full or the stream is not running), and `tuh_audio_read_available()` / `tuh_audio_write_available()` report the FIFO occupancy in frames. `tuh_audio_write()` only queues data; the playback transfer-completion chain sends it, or sends silence when the FIFO does not contain a complete polling interval without consuming the partial data. +- Isochronous transfers require the host to poll `tuh_task()` continuously; the capture FIFO absorbs short scheduling gaps and overwrites the oldest frames when full. |