Freescale Semiconductor MC68HC908MR16 Datasheet page 178

Serial Communications Interface Module (SCI)
SCR2–SCR0 — SCI Baud Rate Select Bits
These read/write bits select the SCI baud rate divisor as shown in
SCR2–SCR0.
Use this formula to calculate the SCI baud rate:
where:
f = internal operating frequency
OP
PD = prescaler divisor
BD = baud rate divisor
Table 13-7 shows the SCI baud rates that can be generated with a 4.9152-MHz crystal with the CGM set
for an f of 7.3728 MHz and the CGM set for an f
OP
178
Table 13-6. SCI Baud Rate Selection
SCR2:SCR1:SCR0
000
001
010
011
100
101
110
111
f OP
Baud rate = ----------------------------------- -
×
64 PD BD
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Baud Rate Divisor (BD)
1
2
4
8
16
32
64
128
×
of 4.9152 MHz.
OP
Table 13-6. Reset clears
Freescale Semiconductor