MC908JL8CDWE Datasheet, PDF (123/212 Pages) Freescale Semiconductor, Inc – Microcontrollers

Functional Description
Addr.
Register Name
$0013
Read:
SCI Control Register 1
(SCC1)
Write:
Reset:
$0014
Read:
SCI Control Register 2
(SCC2)
Write:
Reset:
$0015
Read:
SCI Control Register 3
(SCC3)
Write:
Reset:
Read:
$0016 SCI Status Register 1 (SCS1) Write:
Reset:
Read:
$0017 SCI Status Register 2 (SCS2) Write:
Reset:
$0018
Read:
SCI Data Register
(SCDR)
Write:
Reset:
$0019
Read:
SCI Baud Rate Register
(SCBR)
Write:
Reset:
Bit 7
LOOPS
0
SCTIE
0
R8
U
SCTE
1
0
R7
T7
0
0
6
ENSCI
0
TCIE
0
T8
U
TC
1
5
TXINV
0
SCRIE
0
DMARE
0
SCRF
4
M
0
ILIE
0
DMATE
0
IDLE
0
0
3
WAKE
0
TE
0
ORIE
0
OR
0
0
0
R6
R5
T6
T5
0
SCP1
0
0
= Unimplemented
0
0
R4
R3
T4
T3
Unaffected by reset
SCP0
R
0
0
R = Reserved
2
1
ILTY
PEN
0
0
RE
RWU
0
0
NEIE
FEIE
0
0
NF
FE
0
0
BKF
0
0
R2
R1
T2
T1
SCR2
SCR1
0
0
U = Unaffected
Figure 9-2. SCI I/O Register Summary
Bit 0
PTY
0
SBK
0
PEIE
0
PE
0
RPF
0
R0
T0
SCR0
0
9.4 Functional Description
Figure 9-1 shows the structure of the SCI module. The SCI allows full-duplex, asynchronous, NRZ serial
communication among the MCU and remote devices, including other MCUs. The transmitter and receiver
of the SCI operate independently, although they use the same baud rate generator. During normal
operation, the CPU monitors the status of the SCI, writes the data to be transmitted, and processes
received data. The baud rate clock source for the SCI is the bus clock.
9.4.1 Data Format
The SCI uses the standard non-return-to-zero mark/space data format illustrated in Figure 9-3.
8-BIT DATA FORMAT
BIT M IN SCC1 CLEAR
PARITY
BIT
NEXT
START
START
BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 ^STOP BIT
BIT
START
9-BIT DATA FORMAT
BIT M IN SCC1 SET
PARITY
BIT
NEXT
START
BIT BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 BIT 8 STOP BIT
BIT
Figure 9-3. SCI Data Formats
MC68HC908JL8/JK8 • MC68HC08JL8/JK8 • MC68HC908KL8 Data Sheet, Rev. 3.1
Freescale Semiconductor
123