30.10.13 HBI Channel Busy 0 Register
The HC can determine which channel(s) are busy by reading the HBI Channel Busy Registers (HCBRn). An HBI channel is busy if:
- It is currently loaded into one of the two AGUs
- The channel is enabled, CE = 1 from the Channel Allocation Table, and
- The DMA is active
When an HBI channel is busy, hardware may write back its local copy of the channel descriptor at any time. System software should not write a CDT descriptor for a channel that is busy. Only two HBI channels can be busy at any given time. Each bit of HCBRn is read-only.
| Symbol | Description | Symbol | Description | Symbol | Description |
|---|---|---|---|---|---|
| R | Readable bit | HC | Cleared by Hardware | (Grey cell) | Unimplemented |
| W | Writable bit | HS | Set by Hardware | X | Bit is unknown at Reset |
| K | Write to clear | S | Software settable bit | — | — |
| Name: | HCBR0 |
| Offset: | 0x498 |
| Reset: | 0x00000000 |
| Property: | Read-only |
| Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
| CHB [31:24] | |||||||||
| Access | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
| CHB [23:16] | |||||||||
| Access | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| CHB [15:8] | |||||||||
| Access | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| CHB [7:0] | |||||||||
| Access | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | R/HS/HC | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bits 31:0 – CHB [31:0] Bitwise Channel Busy Bit [31:0]
CHB[n] = 1 indicates that channel n is busy.