MC68HC08AS20 Datasheet, PDF (237/386 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

17.4.1 Data Format
The SCI uses the standard non-return-to-zero mark/space data format
illustrated in Figure 17-2.
8-BIT DATA FORMAT
(BIT M IN SCC1 CLEAR)
POSSIBLE
PARITY
BIT
NEXT
START
BIT BIT 0
BIT 1
BIT 2
BIT 3
BIT 4
BIT 5
BIT 6
BIT 7
START
STOP BIT
BIT
START
BIT BIT 0
BIT 1
BIT 2
9-BIT DATA FORMAT
(BIT M IN SCC1 SET)
BIT 3 BIT 4 BIT 5 BIT 6
POSSIBLE
PARITY
BIT
BIT 7 BIT 8 STOP
BIT
NEXT
START
BIT
Figure 17-2. SCI Data Formats
17.4.2 Transmitter
Figure 17-3 shows the structure of the SCI transmitter.
17.4.3 Character Length
The transmitter can accommodate either 8-bit or 9-bit data. The state of
the M bit in SCI control register 1 (SCC1) determines character length.
When transmitting 9-bit data, bit T8 in SCI control register 3 (SCC3) is
the ninth bit (bit 8).
MC68HC08AS20 — Rev. 4.1
Freescale Semiconductor
Advance Information
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