MC68HC908GR16A Datasheet, PDF (168/270 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Enhanced Serial Communications Interface (ESCI) Module
Table 14-11. ESCI Prescaler Divisor Fine Adjust (Continued)
PSSB[4:3:2:1:0]
Prescaler Divisor Fine Adjust (PDFA)
10000
10001
16/32 = 0.5
17/32 = 0.53125
10010
18/32 = 0.5625
10011
19/32 = 0.59375
10100
20/32 = 0.625
10101
10110
21/32 = 0.65625
22/32 = 0.6875
10111
23/32 = 0.71875
11000
24/32 = 0.75
11001
11010
25/32 = 0.78125
26/32 = 0.8125
11011
27/32 = 0.84375
11100
28/32 = 0.875
11101
29/32 = 0.90625
11110
11111
30/32 = 0.9375
31/32 = 0.96875
Use the following formula to calculate the ESCI baud rate:
Frequency of the SCI clock source
Baud rate = _{64 x BPD x BD x (PD + PDFA)}
where:
Frequency of the SCI clock source = f_Bus or CGMXCLK (selected by
ESCIBDSRC in the CONFIG2 register)
BPD = Baud rate register prescaler divisor
BD = Baud rate divisor
PD = Prescaler divisor
PDFA = Prescaler divisor fine adjust
Table 14-12 shows the ESCI baud rates that can be generated with a 4.9152-MHz bus frequency.
MC68HC908GR16A Data Sheet, Rev. 1.0
168
Freescale Semiconductor