Sci Control Register 1 (Scixc1) - ROHS MC9S08QE128 Reference Manual

Serial Communications Interface (S08SCIV4)
7
R
SBR7
W
Reset 0
Field
7:0 Baud Rate Modulo Divisor — These 13 bits in SBR[12:0] are referred to collectively as BR, and they set the
SBR[7:0] modulo divide rate for the SCI baud rate generator. When BR = 0, the SCI baud rate generator is disabled to
reduce supply current. When BR = 1 to 8191, the SCI baud rate = BUSCLK/(16×BR). See also BR bits in
Table 14-1.
14.2.2

SCI Control Register 1 (SCIxC1)

This read/write register is used to control various optional features of the SCI system.
7
R
LOOPS
W
Reset 0
Field
7 Loop Mode Select — Selects between loop back modes and normal 2-pin full-duplex modes. When
LOOPS LOOPS = 1, the transmitter output is internally connected to the receiver input.
0 Normal operation — RxD and TxD use separate pins.
1 Loop mode or single-wire mode where transmitter outputs are internally connected to receiver input. (See
RSRC bit.) RxD pin is not used by SCI.
6 SCI Stops in Wait Mode
SCISWAI 0 SCI clocks continue to run in wait mode so the SCI can be the source of an interrupt that wakes up the CPU.
1 SCI clocks freeze while CPU is in wait mode.
5 Receiver Source Select — This bit has no meaning or effect unless the LOOPS bit is set to 1. When
RSRC LOOPS = 1, the receiver input is internally connected to the TxD pin and RSRC determines whether this
connection is also connected to the transmitter output.
0 Provided LOOPS = 1, RSRC = 0 selects internal loop back mode and the SCI does not use the RxD pins.
1 Single-wire SCI mode where the TxD pin is connected to the transmitter output and receiver input.
4 9-Bit or 8-Bit Mode Select
M 0 Normal — start + 8 data bits (LSB first) + stop.
1 Receiver and transmitter use 9-bit data characters
start + 8 data bits (LSB first) + 9th data bit + stop.
254
6 5
SBR6 SBR5
0 0
Figure 14-6. SCI Baud Rate Register (SCIxBDL)
Table 14-2. SCIxBDL Field Descriptions
6 5
SCISWAI RSRC
0 0
Figure 14-7. SCI Control Register 1 (SCIxC1)
Table 14-3. SCIxC1 Field Descriptions
MC9S08QE128 MCU Series Reference Manual, Rev. 2
4 3
SBR4 SBR3
0 0
Description
4 3
M WAKE
0 0
Description
2 1
SBR2 SBR1
1 0
2 1
ILT PE
0 0
Freescale Semiconductor
0
SBR0
0
0
PT
0