MC9S12XD256CAL Datasheet, PDF (495/1348 Pages) Freescale Semiconductor, Inc – This specification describes the function of the clocks and reset generator (CRG).

Chapter 11 Serial Communication Interface (S12SCIV5)
11.4.3 Data Format
The SCI uses the standard NRZ mark/space data format. When Infrared is enabled, the SCI uses RZI data
format where zeroes are represented by light pulses and ones remain low. See Figure 11-15 below.
Start
Bit
Bit 0
Bit 1
Bit 2
8-Bit Data Format
(Bit M in SCICR1 Clear)
Possible
Parity
Bit
Bit 3 Bit 4 Bit 5 Bit 6 Bit 7 STOP
Bit
Next
Start
Bit
Standard
SCI Data
Infrared
SCI Data
Start
Bit
Bit 0
Bit 1
Bit 2
9-Bit Data Format
(Bit M in SCICR1 Set)
Bit 3 Bit 4 Bit 5 Bit 6
POSSIBLE
PARITY
Bit
Bit 7 Bit 8 STOP
Bit
NEXT
START
Bit
Standard
SCI Data
Figure 11-15. SCI Data Formats
Infrared
SCI Data
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.
Table 11-13. 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
1¹
0
1
1 _{The address bit identifies the frame as an address}
character. See Section 11.4.6.6, “Receiver Wakeup”.
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 11-14. Example of 9-Bit Data Formats
Start
Bit
1
1
1
Data
Bits
9
8
8
Address
Bits
0
0
1¹
Parity
Bits
0
1
0
Stop
Bit
1
1
1
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor
495