MC68HC11P2 Datasheet, PDF (95/268 Pages) Motorola, Inc – Microcontrollers

Freescale Semiconductor, Inc.
Serial Communications Interface (SCI)
SCI registers
Table 5-1. Example SCI baud rate control values
Target
baud
rate
110
150
300
600
1 200
2 400
4 800
9 600
19 200
38 400
Crystal frequency (EXTAL)
8 MHz
12 MHz
16 MHz
Dec
value
Hex
value
Dec
value
Hex
value
Dec
value
Hex
value
2272 $08E0 3409 $0D51 4545 $11C1
1666 $0682 2500 $09C4 3333 $0D05
833 $0341 1250 $04E2 1666 $0682
416 $01A0 625 $0271 833 $0341
208 $00D0 312 $0138 416 $01A0
104 $0068 156 $009C 208 $00D0
52
$0034
78
$004E 104 $0068
26
$001A
39
$0027
52
$0034
13
$000D
20
$0014
26
$001A
13
$000D
5.8.2 SCCR1 — SCI control register 1
SCI 1 control 1 (SCCR1)
Address bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
State
on reset
$0072
LOOP
S
WOMS
0
M WAKE ILT PE PT 0000 0000
The SCCR1 register provides the control bits that determine word length
and select the method used for the wakeup feature.
LOOPS — SCI loop mode enable
1 = SCI transmit and receive are disconnected from TXD and RXD
pins, and transmitter output is fed back into the receiver input.
0 = SCI transmit and receive operate normally.
Both the transmitter and receiver must be enabled to use the LOOP
mode. When the LOOP mode is enabled, the TXD pin is driven high
(idle line state) if the transmitter is enabled.
WOMS — Wired-OR mode for SCI pins (PD1, PD0)
1 = TXD and RXD are open drains if operating as outputs.
0 = TXD and RXD operate normally.
MC68HC11P2 — Rev 1.0
Serial Communications Interface (SCI)
For More Information On This Product,
Go to: www.freescale.com
Technical Data