S912XEG128J2MAA Datasheet, PDF (729/1324 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 20 Serial Communication Interface (S12SCIV5)
Table 20-3. IRSCI Transmit Pulse Width
TNP[1:0]
11
10
01
00
Narrow Pulse Width
1/4
1/32
1/16
3/16
20.3.2.2 SCI Control Register 1 (SCICR1)
Module Base + 0x0002
7
6
5
4
3
2
1
0
R
LOOPS
SCISWAI
RSRC
M
WAKE
ILT
PE
PT
W
Reset
0
0
0
0
0
0
0
0
Figure 20-5. SCI Control Register 1 (SCICR1)
Read: Anytime, if AMAP = 0.
Write: Anytime, if AMAP = 0.
NOTE
This register is only visible in the memory map if AMAP = 0 (reset
condition).
Table 20-4. SCICR1 Field Descriptions
Field
Description
7
LOOPS
6
SCISWAI
5
RSRC
4
M
3
WAKE
Loop Select Bit — LOOPS enables loop operation. In loop operation, the RXD pin is disconnected from the SCI
and the transmitter output is internally connected to the receiver input. Both the transmitter and the receiver must
be enabled to use the loop function.
0 Normal operation enabled
1 Loop operation enabled
The receiver input is determined by the RSRC bit.
SCI Stop in Wait Mode Bit — SCISWAI disables the SCI in wait mode.
0 SCI enabled in wait mode
1 SCI disabled in wait mode
Receiver Source Bit — When LOOPS = 1, the RSRC bit determines the source for the receiver shift register
input. See Table 20-5.
0 Receiver input internally connected to transmitter output
1 Receiver input connected externally to transmitter
Data Format Mode Bit — MODE determines whether data characters are eight or nine bits long.
0 One start bit, eight data bits, one stop bit
1 One start bit, nine data bits, one stop bit
Wakeup Condition Bit — WAKE determines which condition wakes up the SCI: a logic 1 (address mark) in the
most significant bit position of a received data character or an idle condition on the RXD pin.
0 Idle line wakeup
1 Address mark wakeup
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor
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