MC68HC908GR8A_07 Datasheet, PDF (155/260 Pages) Freescale Semiconductor, Inc – Microcontrollers

I/O Registers
SCR2–SCR0 — SCI Baud Rate Select Bits
These read/write bits select the SCI baud rate divisor as shown in Table 13-7. Reset clears
SCR2–SCR0.
Table 13-7. SCI Baud Rate Selection
SCR2, SCR1, and SCR0
000
001
010
011
100
101
110
111
Baud Rate Divisor (BD)
1
2
4
8
16
32
64
128
Use this formula to calculate the SCI baud rate:
Baud rate = ^{S----C-----I---c---l--o---c---k-----s---o---u---r--c---e--}
64 × PD × BD
where:
SCI clock source = f_BUS or CGMXCLK (selected by SCIBDSRC bit in CONFIG2)
PD = prescaler divisor
BD = baud rate divisor
Table 13-8 shows the SCI baud rates that can be generated with a 4.9152-MHz bus clock when f_BUS is
selected as SCI clock source.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Freescale Semiconductor
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