
MC68HC11A8
MC68HC11A8TS/D
MOTOROLA
25
TCLR — Clear Baud Rate Counters (TEST)
SCP1, SCP0 — SCI Baud Rate Prescaler Selects
RCKB — SCI Baud Rate Clock Check (TEST)
SCR2, SCR1, and SCR0 — SCI Baud Rate Selects
Selects receiver and transmitter bit rate based on output from baud rate prescaler stage.
BAUD
— Baud Rate
$102B
Bit 7
TCLR
0
6
0
0
5
4
3
2
1
Bit 0
SCR0
U
SCP1
0
SCP0
0
RCKB
0
SCR2
U
SCR1
U
RESET:
SCP[1:0]
Divide
Internal
Clock
By
1
3
4
13
Crystal Frequency in MHz
8.0 MHz
(Baud)
4.0 MHz
(Baud)
10.0 MHz
(Baud)
12.0 MHz
(Baud)
00
01
10
11
62.50K
20.83K
15.625K
4800
125.0K
41.67K
31.25K
9600
156.25K
52.08K
38.4K
12.02K
187.5K
62.5K
46.88K
14.42K
SCP[2:0]
Divide
Prescaler
By
Highest Baud Rate
(Prescaler Output from Previous Table)
4800
9600
4800
9600
2400
4800
1200
2400
600
1200
300
600
150
300
—
150
—
—
38.4K
38.4K
19.2K
9600
4800
2400
1200
600
300
000
001
010
011
100
101
110
111
1
2
4
8
16
32
64
128