MC68HC908AP64_07 FREESCALE [Freescale Semiconductor, Inc], MC68HC908AP64_07 Datasheet - Page 178

• Manufacturer Part Number: MC68HC908AP64_07
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Serial Communications Interface Module (SCI)
11.8.7 SCI Baud Rate Register
The baud rate register (SCBR) selects the baud rate for both the receiver and the transmitter.
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:
178
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.
SCI clock source = f
(selected by SCIBDSRC bit in CONFIG2 register)
PD = prescaler divisor
BD = baud rate divisor
Address:
Reset:
Read:
Write:
$0019
BUS
0
0
SCR2, SCR1, and SCR0
SCP1 and SCP0
or CGMXCLK
Figure 11-16. SCI Baud Rate Register (SCBR)
= Unimplemented
00
01
10
11
Table 11-6. SCI Baud Rate Prescaling
baud rate
Table 11-7. SCI Baud Rate Selection
6
0
0
MC68HC908AP Family Data Sheet, Rev. 4
000
001
010
011
100
101
110
111
SCP1
=
5
0
SCI clock source
-------------------------------------------- -
64 PD BD
×
SCP0
4
0
×
Prescaler Divisor (PD)
Baud Rate Divisor (BD)
R
R
3
0
13
1
3
4
= Reserved
128
SCR2
16
32
64
1
2
4
8
2
0
Table
Table
11-7. Reset clears
SCR1
1
0
11-6. Reset clears SCP1
Freescale Semiconductor
SCR0
Bit 0
0