MC908QY8CDWE Datasheet, PDF (114/232 Pages) Freescale Semiconductor, Inc – Addendum to MC68HC908QB8, rev. 3

Enhanced Serial Communications Interface (ESCI) Module
13.3.1 Data Format
The SCI uses the standard mark/space non-return-to-zero (NRZ) format illustrated in Figure 13-3.
PARITY
START
8-BIT DATA FORMAT
(BIT M IN SCC1 CLEAR)
OR DATA
BIT
NEXT
START
BIT _{BIT 0 BIT 1 BIT 2 BIT 3 BIT 4 BIT 5 BIT 6 BIT 7 STOP BIT}
BIT
PARITY
START
9-BIT DATA FORMAT
(BIT M IN SCC1 SET)
OR DATA
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 13-3. SCI Data Formats
13.3.2 Transmitter
Figure 13-4 shows the structure of the SCI transmitter.
INTERNAL BUS
÷4
SCP1
SCP0
SCR2
SCR1
SCR0
PRE-
BAUD
SCALER DIVIDER
÷ 16
ESCI DATA REGISTER
11-BIT
TRANSMIT
SHIFT REGISTER
STOP 8 7 6 5 4 3 2 1 0 START
TXINV
BUSCLKX4
OR
BUS CLOCK
PDS2
PDS1
PDS0
PSSB4
PSSB3
PSSB2
PSSB1
PSSB0
TRANSMITTER
INTERRUPT REQUEST
M
PEN
PARITY
PTY
GENERATION
T8
TRANSMITTER
CONTROL LOGIC
SCTE
SCTE
SCTIE
TC
TCIE
SCTIE
TC
TCIE
Figure 13-4. ESCI Transmitter
SBK
LOOPS
ENSCI
TE
LINT
SCI_TxD
MC68HC908QB8 Data Sheet, Rev. 3
112
Freescale Semiconductor