EXTAL
XTAL
INTERNAL BUS CLOCK (PH2)
OSCILLATOR
AND
CLOCK GENERATOR
÷3
÷4
÷13
(÷4)
SCP[1:0]
1:1
0:0
0:1
1:0
E
AS
SCR[2:0]
0:0:0
÷2
÷2
÷2
÷2
÷2
÷2
÷2
0:0:1
0:1:0
0:1:1
1:0:0
1:0:1
1:1:0
1:1:1
÷16
SCI
TRANSMIT
BAUD RATE
(1X)
SCI
RECEIVE
BAUD RATE
(16X)
SCI BAUD GENERATOR
Figure 8 SCI Baud Rate Diagram
SCCR1 — SCI Control Register 1
$102C
Bit 7
R8
U
6
T8
U
5
0
0
4
M
0
3
WAKE
0
2
0
0
1
0
0
Bit 0
0
0
RESET:
R8 — Receive Data Bit 8
If M bit is set, R8 stores ninth bit in receive data character.
T8 — Transmit Data Bit 8
If M bit is set, T8 stores ninth bit in transmit data character.
M — Mode (Select Character Format)
0 = Start bit, 8 data bits, 1 stop bit
1 = Start bit, 9 data bits, 1 stop bit
MOTOROLA
26
MC68HC11A8
MC68HC11A8TS/D
MOTOROLA [ MOTOROLA ]
