18.7.9 DFLL48M Control B

Note: During a maximum 30 cycles of the reference clock period, between lock flag asserted and frequency stabilization, DFLL accuracy will be limited to +/-1.5%. After frequency stabilization has been achieved, the accuracy will be +/-0.25%. Disabling Quick Lock plus reducing STEP value at 4 (instead of the optimum 8) will eliminate this clock period of inaccuracy.
Table 18-12. Register Bit Attribute Legend
SymbolDescriptionSymbolDescriptionSymbolDescription
RReadable bitHCCleared by Hardware(Grey cell)Unimplemented
WWritable bitHSSet by HardwareXBit is unknown at Reset
KWrite to clearSSoftware settable bit
Name: DFLLCTRLB
Offset: 0x30
Reset: 0x00000000
Property: PAC Write-Protected, Write-Synchronized

Bit 3130292827262524 
          
Access  
Reset  
Bit 2322212019181716 
          
Access  
Reset  
Bit 15141312111098 
          
Access  
Reset  
Bit 76543210 
 WAITLOCK QLDISCCDIS LLAWSTABLELOOPEN 
Access R/WR/WR/WR/WR/WR/W 
Reset 000000 

Bit 7 – WAITLOCK Wait Lock

This bit controls the DFLL48M output clock, depending on lock status:

ValueDescription
0Output clock before the DFLL is locked.
1Output clock when DFLL is locked.

Bit 5 – QLDIS Quick Lock Disable

ValueDescription
0Quick Lock is enabled.
1Quick Lock is disabled.

Bit 4 – CCDIS Chill Cycle Disable

ValueDescription
0Chill Cycle is enabled.
1Chill Cycle is disabled.

Bit 2 – LLAW Lose Lock After Wake

ValueDescription
0Locks will not be lost after waking up from sleep modes if the DFLL clock has been stopped.
1Locks will be lost after waking up from sleep modes if the DFLL clock has been stopped.

Bit 1 – STABLE Stable DFLL48M Frequency

ValueDescription
0Tune register tracks changes in output frequency.
1Tune calibration register value will be fixed after a lock.

Bit 0 – LOOPEN Operating Mode Selection

ValueDescription
0The DFLL operates in open-loop operation.
1The DFLL operates in closed-loop operation.