From SLUUC81 Section 12.2.30
XL (Bit 22): 400-kHz mode
1 = Active
0 = Inactive
From SLUUC81 Section 12.3.1
Bit 3: XL—Enable 400-kHz COM mode
0 = Normal bus speed (default)
1 = 400-kHz bus speed (slave mode)
Slave mode maximum speed is clearly indicated in the datasheet for the part.
Question: What is Normal bus speed (default) ?
Given that SLUUC81 refers to SMbus I am hoping that it is 100 kHz but I can't find it stated anywhere.