MC68HC11KA4TS Datasheet, PDF (40/68 Pages) Motorola, Inc – 8-Bit Microcontroller

SCBDH/L —SCI Baud Rate Control High/Low
$0070
RESET:
$0071
RESET:
Bit 7
BTST
0
SBR7
0
6
BSPL
0
SBR6
0
5
—
0
SBR5
0
4
SBR12
0
SBR4
0
3
SBR11
0
SBR3
0
2
SBR10
0
SBR2
1
1
SBR9
0
SBR1
0
$0070, $0071
Bit 0
SBR8
0
SBR0
0
High
Low
BTST — Baud Register Test (TEST)
BSPL — Baud Rate Counter Split (TEST)
Bit 5 — Not implemented
Always reads zero
SBR[12:0] — SCI Baud Rate Selects
Use the following formula to calculate SCI baud rate. Refer to the table of baud rate control values for
example rates:
SCI baud rate = EXTAL ÷[16 (2 BR)]
Where BR is the contents of SCBDH, L (BR = 1, 2, 3, ..., 8191).
BR = 0 disables the baud rate generator.
Target
Baud
Rate
110
150
300
600
1200
2400
4800
9600
19.2 K
38.4 K
Table 7 SCI Baud Rate Control Values
8 MHz
Dec Value
Hex Value
2272
$08E0
1666
$0682
833
$0341
416
$01A0
208
$00D0
104
$0068
52
$0034
26
$001A
13
$000D
—
—
Crystal Frequency (EXTAL)
12 MHz
Dec Value
Hex Value
3409
$0D51
2500
$09C4
1250
$04E2
625
$0271
312
$0138
156
$009C
78
$004E
39
$0027
20
$0014
—
—
16 MHz
Dec Value
Hex Value
4545
$11C1
3333
$0D05
1666
$0682
833
$0341
416
$01A0
208
$00D0
104
$0068
52
$0034
26
$001A
13
$000D
SCCR1 —SCI Control 1
$0072
Bit 7
6
5
LOOPS WOMS
—
RESET:
0
0
0
4
3
2
1
Bit 0
M
WAKE
ILT
PE
PT
0
0
0
0
0
LOOPS — SCI LOOP Mode Enable
0 = SCI transmit and receive operate normally
1 = SCI transmit and receive are disconnected from TxD and RxD pins, and transmitter output is
fed back into the receiver input
MOTOROLA
40
MC68HC11KA4
MC68HC11KA4TS/D