25.9.2 DMA Control B Register

Table 25-7. Register Bit Attribute Legend
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: CTRLB
Offset: 0x04
Reset: 0x00000000
Property: PAC Write-Protection

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
       QOS2[1:0] 
Access R/WR/W 
Reset 00 
Bit 15141312111098 
       QOS1[1:0] 
Access R/WR/W 
Reset 00 
Bit 76543210 
       QOS0[1:0] 
Access R/WR/W 
Reset 00 

Bits 0:1, 8:9, 16:17 – QOSn Priority Group n QOS control [n=1..3]

Sets the Quality of service level for Channel Priority Group n. Setting this value affects arbitration within the device bus fabric. This value does not affect arbitration within the DMA.

Note: DMA0 has 3 priority levels, DMA1 has 2 priority levels.
Table 25-8. Generator Clock Source Selection
Value Name Description
0x0 LEVEL_0 QoS level is 0 (lowest)
0x1 LEVEL_1 QoS level is 1 (lower)
0x2 LEVEL_2 QoS level is 2 (medium)
0x3 LEVEL_3 QoS level is 3 (high)