ADV7511W

The ADV7511W Programming Guide states that some fixed registers need to be changed from their default values. If they are fixed, how can they be changed? Pages 160 and 161 show a number of these. The registers are 0x98, 0x9A, 0x9C, 0x9D, 0xA2 and 0xA3. Do these registers need to be written to for proper operation?