On page 45, formula 22.
my Ufs = 775.84, Un = 110, then
VLEVEL = 775.84/110*4000000 = 2.8212*10^7 = 0x1AE7B20
which is 4 bytes value. How should I put it in the signed 24 bits register of VLEVEL?
VLEVEL is a signed 28-bit register. It is a mistake and will be corrected in the next revision of the datasheet. So, you should be fine, I believe.
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