MC68HC908KX8 Datasheet, PDF (185/310 Pages) Motorola, Inc – Microcontrollers

Serial Communications Interface Module (SCI)
Functional Description
INTERNAL BUS
÷4
PRE- BAUD
SCALER DIVIDER
÷ 16
SCI DATA REGISTER
SCP1
SCP0
SCR1
SCR2
SCR0
11-BIT
TRANSMIT
SHIFT REGISTER
H8 7 6 5 4 3 2 1 0 L
TxD
TXINV
M
PEN
PARITY
PTY
GENERATION
T8
TRANSMITTER
CONTROL LOGIC
SCTE
SCTIE
TC
TCIE
SCTE
SCTIE
TC
TCIE
SBK
LOOPS
ENSCI
TE
Figure 14-4. SCI Transmitter Break Characters
3. Clear the SCI transmitter empty bit by first reading SCI status
register 1 (SCS1) and then writing to the SCDR.
4. Repeat step 3 for each subsequent transmission.
At the start of a transmission, transmitter control logic automatically
loads the transmit shift register with a preamble of logic 1s. After the
preamble shifts out, control logic transfers the SCDR data into the
transmit shift register. A logic 0 start bit automatically goes into the least
significant bit position of the transmit shift register. A logic 1 stop bit goes
into the most significant bit position.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
Serial Communications Interface Module (SCI)
Technical Data
185