Chapter 20 Serial Communication Interface (S12SCIV5)
MC9S12XE-Family Reference Manual , Rev. 1.19
740
Freescale Semiconductor
Figure 20-15. SCI Data Formats
Each data character is contained in a frame that includes a start bit, eight or nine data bits, and a stop bit.
Clearing the M bit in SCI control register 1 configures the SCI for 8-bit data characters. A frame with eight
data bits has a total of 10 bits. Setting the M bit configures the SCI for nine-bit data characters. A frame
with nine data bits has a total of 11 bits.
When the SCI is configured for 9-bit data characters, the ninth data bit is the T8 bit in SCI data register
high (SCIDRH). It remains unchanged after transmission and can be used repeatedly without rewriting it.
A frame with nine data bits has a total of 11 bits.
Table 20-14. Example of 8-Bit Data Formats
Start
Bit
Data
Bits
Address
Bits
Parity
Bits
Stop
Bit
1
8
0
0
1
1
7
0
1
1
1
7
1
(1)
1. The address bit identifies the frame as an address
character. See
Section 20.4.6.6, “Receiver Wakeup”
.
0
1
Table 20-15. Example of 9-Bit Data Formats
Start
Bit
Data
Bits
Address
Bits
Parity
Bits
Stop
Bit
1
9
0
0
1
1
8
0
1
1
1
8
1
(1)
1. The address bit identifies the frame as an address
character. See
Section 20.4.6.6, “Receiver Wakeup”
.
0
1
Bit 5
Start
Bit
Bit 0
Bit 1
Next
STOP
Bit
Start
Bit
8-Bit Data Format
(Bit M in SCICR1 Clear)
Start
Bit
Bit 0
NEXT
STOP
Bit
START
Bit
9-Bit Data Format
(Bit M in SCICR1 Set)
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Bit 8
Bit 2
Bit 3
Bit 4
Bit 6
Bit 7
POSSIBLE
PARITY
Bit
Possible
Parity
Bit
Standard
SCI Data
Infrared
SCI Data
Standard
SCI Data
Infrared
SCI Data
Because
of
an
order
from
the
United
States
International
Trade
Commission,
BGA-packaged
product
lines
and
part
numbers
indicated
here
currently
are
not
available
from
Freescale
for
import
or
sale
in
the
United
States
prior
to
September
2010:
S12XE
products
in
208
MAPBGA
packages
