
Serial Communications Interface (SCI)
Technical Data
MC68HC908AZ60A — Rev 2.0
280
Serial Communications Interface (SCI)
MOTOROLA
SCP1 and SCP0 — SCI Baud Rate Prescaler Bits
These read/write bits select the baud rate prescaler divisor as shown
SCR2 – SCR0 — SCI Baud Rate Select Bits
These read/write bits select the SCI baud rate divisor as shown in
Use the following formula to calculate the SCI baud rate:
where:
fCrystal = crystal frequency
PD = prescaler divisor
BD = baud rate divisor
Table 18-9. SCI Baud Rate Prescaling
SCP[1:0]
Prescaler Divisor (PD)
00
1
01
3
10
4
11
13
Table 18-10. SCI Baud Rate Selection
SCR[2:1:0]
Baud Rate Divisor (BD)
000
1
001
2
010
4
011
8
100
16
101
32
110
64
111
128
Baud rate
fCrystal
64
PD
BD
×
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