DEVOSC Start-up time question

Brad Caldwell said:

In the DM8148 datasheet,

Table 7-11 Start-up time (from power up until oscillating at stable frequency) : 4 ms.

Is this from 1.8V ramp, or 1.2V ramp?  In other words what does power up mean?

My interpretation of "power up" is that it means the power supply rails are stable to their regulated values, and not in the process of ramping.
An indirect illustration would be the diagram in Figure 7-4 of the datasheet entitled "Power-Up Timing".  You see the DEV and AUX clocks depicted as stable well after the power supplies are stable.

Brad Caldwell said:

The xtal is already up by the time 1.2V ramps. So in our application it’s < 0 ms.

This isn't specifically relevant.  The DEVOSC_MXI and DEVOSC_MXO are powered by the 1.8V supply rail VDDA_1P8 as indicated in Table 3-34 of the datasheet.