25.10.1 Channel Control A Register
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: | CHCTRLAk |
Offset: | 0x50 + k*0x50 [k=0..15] |
Reset: | 0x00000000 |
Property: | PAC Write-Protection |
Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
RUNSTDBY | |||||||||
Access | R/W | ||||||||
Reset | 0 |
Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
SWFRC | |||||||||
Access | W | ||||||||
Reset | 0 |
Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
LLEN | |||||||||
Access | R/W/HC | ||||||||
Reset | 0 |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
ENABLE | |||||||||
Access | R/W/HC | ||||||||
Reset | 0 |
Bit 24 – RUNSTDBY Run in Standby
This bit is used to keep the DMA channel running in standby mode:
Value | Description |
---|---|
0 | The channel is halted in standby. |
1 | The channel continues to run in standby. Continue module operation in idle/sleep mode. |
Bit 16 – SWFRC Software Force Trigger
Write to 1 to issue a start trigger to the channel. Reading this bit always returns 0.
Bit 8 – LLEN Linked List Enable
Value | Description |
---|---|
0 | |
1 | DMA will load the next descriptor at address location to by CHNXTk.NXT[31:0] on completion of the current block transfer or if the channel is idle (i.e. CHCTRLAk.ENABLE=0 and CHSTATk.BLK-BUSY=0). If CHNXTk.NXT[31:0] = 0xFFFF_FFFF (NULL) the DMA will set the CHINTFk.LL status bit and clear LLEN. No further action takes place. |
Bit 0 – ENABLE Channel Enable
Writing a 1 to ENABLE enables a block transfer. Upon completion or abort of the block transfer the DMA clears ENABLE.
Value | Description |
---|---|
0 | Disable channel block transfers or suspend block transfer if CHSTATk.BLKBUSY=1. |
1 | Block transfer enabled. The DMA will initiate a block transfer on the start trigger selected by CHCTRLBk.TRIG or a software trigger, CHCTRLAk.SWFRC=1. |