CSND Shared Memory
This page describes the structure of the CSND shared memory.
Type0 Command Structure
| Index Byte | Description |
|---|---|
| 0x0-0x1 | Offset in shared-memory for the command to process immediately after this one, when not 0xFFFF. |
| 0x2-0x3 | CommandID |
| 0x4-0x7 | This is initially zero when this command data is written by the user process, once the CSND module finishes processing the command this is set to 0x1. |
| 0x8-0xB | The low 5-bits for this field is the the channel-index. This word is used for command parameters as well. |
| 0xC-0x1F | Command parameters |
Type0 Commands
Command 0x8
| Index Byte | Description |
|---|---|
| 0x2-0x3 | CmdID 0x8 |
| 0xC-0xF | Value for the audio sampling frequency? |
This sets the audio sampling frequency?
Command 0xE
| Index Byte | Description |
|---|---|
| 0x2-0x3 | CmdID 0xE |
| 0x14-0x17 | Physical address for the audio data. |
| 0x1C-0x1F | Total byte-size for the audio data. |
This initializes the CSND channel registers located at: 0x1EC03400 + (channel_index*0x20).