SNAS689A October 2017 – July 2019 LMK04228
PRODUCTION DATA.
This register contains the holdover functions.
BIT | NAME | POR DEFAULT | DESCRIPTION | |
---|---|---|---|---|
7:6 | LOS_TIMEOUT | 0 | This controls the amount of time in which no activity on a CLKin forces a clock switch event. | |
Field Value | Timeout | |||
0 (0x00) | 370 kHz | |||
1 (0x01) | 2.1 MHz | |||
2 (0x02) | 8.8 MHz | |||
3 (0x03) | 22 MHz | |||
5 | LOS_EN | 0 | Enables the LOS (Loss-of-Signal) timeout control. Valid for MOS clock inputs.
0: Disabled 1: Enabled |
|
4 | TRACK_EN | 1 | Enable the DAC to track the PLL1 tuning voltage, optionally for use in holdover mode. After device reset, tracking starts at DAC code = 512.
Tracking can be used to monitor PLL1 voltage in any mode. 0: Disabled 1: Enabled, will only track when PLL1 is locked. |
|
3 | HOLDOVER
_FORCE |
0 | This bit forces holdover mode. When holdover mode is forced, if MAN_DAC_EN = 1, then the DAC will set the programmed MAN_DAC value. Otherwise the tracked DAC value will set the DAC voltage.
0: Disabled 1: Enabled. |
|
2 | MAN_DAC_EN | 1 | This bit enables the manual DAC mode.
0: Automatic 1: Manual |
|
1:0 | MAN_DAC[9:8] | 2 | See MAN_DAC[9:8], MAN_DAC[7:0] for more information on the MAN_DAC settings. |