mc68hc908gr8vp Freescale Semiconductor, Inc, mc68hc908gr8vp Datasheet - Page 184

• Manufacturer Part Number: mc68hc908gr8vp
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Serial Communications Interface (SCI)
SCP1 and SCP0 — SCI Baud Rate Prescaler Bits
SCR2–SCR0 — SCI Baud Rate Select Bits
Use this formula to calculate the SCI baud rate:
where:
SCIBDSRC from the configuration register is an input to the SCI. With SCIBDSRC = 1 to select the bus
clock as the clock source, this makes the formula:
Table 18-8
184
These read/write bits select the baud rate prescaler divisor as shown in
and SCP0.
These read/write bits select the SCI baud rate divisor as shown in
SCR2–SCR0.
f
PD = prescaler divisor
BD = baud rate divisor
BUS
= bus frequency
shows the SCI baud rates that can be generated with a 4.9152-MHz bus clock.
SCR2, SCR1, and SCR0
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
SCP1 and SCP0
Table 18-6. SCI Baud Rate Prescaling
baud rate
Table 18-7. SCI Baud Rate Selection
baud rate
000
001
010
011
100
101
110
111
00
01
10
11
=
=
----------------------------------- -
64
----------------------------------- -
64
×
f BUS
×
PD BD
f BUS
PD BD
×
×
Baud Rate Divisor (BD)
Prescaler Divisor (PD)
128
13
16
32
64
1
3
4
1
2
4
8
Table
Table
18-7. Reset clears
18-6. Reset clears SCP1
Freescale Semiconductor