Part Number:LMK04610
According to the datasheet (page 42, June 2017 version), holdover mode can be entered as a result of CTRL_VCXO Rail detect. The boundaries get compared against the current value as present in the PLL1 storage cell array.
On page 42 it is stated:
"The storage cells array is encoded with a thermometer code and the register values are binary encoded. A conversion must take place before comparing."
My question is this: as I read this, I would expect the current value of the storage cell array to be a measure of the current value of the VCXO control voltage. But how do I calculate the storage cell value into a value representing the actual VCXO control value?
When I read back the storage cells array (no input reference clock connected to either CLKIN0 or CLKIN1) the value returned is 0x00 0x00 0x00 0x00 0x28 (register address 0x66 through 0x6A), which at first glance doesn't seem to be a "thermometer encoded" value. What is the "conversion" that must take place before comparing, which is mentioned in the note on page 42?