MC68HC908GR16 Datasheet, PDF (188/310 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Enhanced Serial Communications Interface (ESCI) Module
Table 14-10. ESCI Prescaler Division Ratio
PS[2:1:0]
000
001
010
011
100
101
110
111
Prescaler Divisor (PD)
Bypass this prescaler
2
3
4
5
6
7
8
PSSB4–PSSB0 — Clock Insertion Select Bits
These read/write bits select the number of clocks inserted in each 32 output
cycle frame to achieve more timing resolution on the average prescaler
frequency as shown in Table 14-11. Reset clears PSSB4–PSSB0.
Use the following formula to calculate the ESCI baud rate:
Baud rate = --------------------S----C-----I---c---l-o----c---k----s---o----u---r--c---e---------------------
64 × BPD × BD × (PD + PDFA)
where:
SCI clock source = f_Bus or CGMXCLK (selected by SCIBDSRC 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.
Data Sheet
188
MC68HC908GR16 — Rev. 1.0
Enhanced Serial Communications Interface (ESCI) Module
For More Information On This Product,
Go to: www.freescale.com
MOTOROLA