MC9S12GRMV1 Datasheet, PDF (678/1292 Pages) Freescale Semiconductor, Inc – MC9S12G Family Reference Manual and Data Sheet

Serial Communication Interface (S12SCIV5)
Table 20-12. SCISR2 Field Descriptions (continued)
Field
3
RXPOL
2
BRK13
1
TXDIR
0
RAF
Description
Receive Polarity — This bit control the polarity of the received data. In NRZ format, a one is represented by a
mark and a zero is represented by a space for normal polarity, and the opposite for inverted polarity. In IrDA
format, a zero is represented by short high pulse in the middle of a bit time remaining idle low for a one for normal
polarity, and a zero is represented by short low pulse in the middle of a bit time remaining idle high for a one for
inverted polarity.
0 Normal polarity
1 Inverted polarity
Break Transmit Character Length — This bit determines whether the transmit break character is 10 or 11 bit
respectively 13 or 14 bits long. The detection of a framing error is not affected by this bit.
0 Break character is 10 or 11 bit long
1 Break character is 13 or 14 bit long
Transmitter Pin Data Direction in Single-Wire Mode — This bit determines whether the TXD pin is going to
be used as an input or output, in the single-wire mode of operation. This bit is only relevant in the single-wire
mode of operation.
0 TXD pin to be used as an input in single-wire mode
1 TXD pin to be used as an output in single-wire mode
Receiver Active Flag — RAF is set when the receiver detects a logic 0 during the RT1 time period of the start
bit search. RAF is cleared when the receiver detects an idle character.
0 No reception in progress
1 Reception in progress
20.3.2.9 SCI Data Registers (SCIDRH, SCIDRL)
Module Base + 0x0006
7
6
5
4
3
2
1
0
R
R8
0
0
0
0
0
0
T8
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 20-12. SCI Data Registers (SCIDRH)
Module Base + 0x0007
7
6
5
4
3
2
1
0
R
R7
R6
R5
R4
R3
R2
R1
R0
W
T7
T6
T5
T4
T3
T2
T1
T0
Reset
0
0
0
0
0
0
0
0
Figure 20-13. SCI Data Registers (SCIDRL)
Read: Anytime; reading accesses SCI receive data register
Write: Anytime; writing accesses SCI transmit data register; writing to R8 has no effect
MC9S12G Family Reference Manual, Rev.1.23
680
Freescale Semiconductor