MC68HC908KX8 Datasheet, PDF (182/310 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface Module (SCI)
14.5 Functional Description
Figure 14-1 shows the structure of the SCI module. The SCI allows full-
duplex, asynchronous, NRZ serial communication between 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.
INTERNAL BUS
SCI DATA
REGISTER
RxD
RECEIVE
SHIFT REGISTER
SCI DATA
REGISTER
TRANSMIT
SHIFT REGISTER
TxD
SCTIE
TCIE
SCRIE
ILIE
TE
RE
RWU
SBK
SCTE
TC
SCRF
IDLE
WAKEUP
CONTROL
TXINV
R
T
OR
NF
FE
PE
LOOPS
RECEIVE
CONTROL
FLAG
CONTROL
LOOPS
ENSCI
ORIE
NEIE
FEIE
PEIE
TRANSMIT
CONTROL
BKF
ENSCI
RPF
BAUDCLK
÷4
PRE- BAUD RATE
SCALER GENERATOR
M
WAKE
ILTY
PEN
PTY
CGMXCLK A
BUSCLK
B
S
SCIBDSRC
÷ 16
DATA SELECTION
CONTROL
Figure 14-1. SCI Module Block Diagram
Technical Data
182
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
Serial Communications Interface Module (SCI)
MOTOROLA