User`s guide

Status Registers
10-2 Modem 3600
Bit values for S-registers must not be confused with the total register
value. Bit values are counted separately for each option group, called bit
mapping, while the register value is the cumulative decimal or
hexadecimal total. The decimal value counts all eight bits as a single
group. Hexadecimal values split the bits into two groups of four each.
Writing to an S-register changes the total value. Figure 10-2 shows the
difference between decimal calculation and hexadecimal calculation.
Figure 10-1. Changing S-Register Values
Figure 10-2. Calculating S-Register Values