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.
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: | DFLLCTRLB |
Offset: | 0x30 |
Reset: | 0x00000000 |
Property: | PAC Write-Protected, Write-Synchronized |
Bit | 31 | 30 | 29 | 28 | 27 | 26 | 25 | 24 | |
Access | |||||||||
Reset |
Bit | 23 | 22 | 21 | 20 | 19 | 18 | 17 | 16 | |
Access | |||||||||
Reset |
Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
Access | |||||||||
Reset |
Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
WAITLOCK | QLDIS | CCDIS | LLAW | STABLE | LOOPEN | ||||
Access | R/W | R/W | R/W | R/W | R/W | R/W | |||
Reset | 0 | 0 | 0 | 0 | 0 | 0 |
Bit 7 – WAITLOCK Wait Lock
This bit controls the DFLL48M output clock, depending on lock status:
Value | Description |
---|---|
0 | Output clock before the DFLL is locked. |
1 | Output clock when DFLL is locked. |
Bit 5 – QLDIS Quick Lock Disable
Value | Description |
---|---|
0 | Quick Lock is enabled. |
1 | Quick Lock is disabled. |
Bit 4 – CCDIS Chill Cycle Disable
Value | Description |
---|---|
0 | Chill Cycle is enabled. |
1 | Chill Cycle is disabled. |
Bit 2 – LLAW Lose Lock After Wake
Value | Description |
---|---|
0 | Locks will not be lost after waking up from sleep modes if the DFLL clock has been stopped. |
1 | Locks will be lost after waking up from sleep modes if the DFLL clock has been stopped. |
Bit 1 – STABLE Stable DFLL48M Frequency
Value | Description |
---|---|
0 | Tune register tracks changes in output frequency. |
1 | Tune calibration register value will be fixed after a lock. |
Bit 0 – LOOPEN Operating Mode Selection
Value | Description |
---|---|
0 | The DFLL operates in open-loop operation. |
1 | The DFLL operates in closed-loop operation. |