mc68hc908gr8b Freescale Semiconductor, Inc, mc68hc908gr8b Datasheet - Page 144

• Manufacturer Part Number: mc68hc908gr8b
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Serial Communications Interface (SCI) Module
13.8 I/O Registers
These I/O registers control and monitor SCI operation:
13.8.1 SCI Control Register 1
SCI control register 1:
LOOPS — Loop Mode Select Bit
ENSCI — Enable SCI Bit
TXINV — Transmit Inversion Bit
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This read/write bit enables loop mode operation. In loop mode the PTE1/RxD pin is disconnected from
the SCI, and the transmitter output goes into the receiver input. Both the transmitter and the receiver
must be enabled to use loop mode. Reset clears the LOOPS bit.
This read/write bit enables the SCI and the SCI baud rate generator. Clearing ENSCI sets the SCTE
and TC bits in SCI status register 1 and disables transmitter interrupts. Reset clears the ENSCI bit.
This read/write bit reverses the polarity of transmitted data. Reset clears the TXINV bit.
1 = Loop mode enabled
0 = Normal operation enabled
1 = SCI enabled
0 = SCI disabled
1 = Transmitter output inverted
0 = Transmitter output not inverted
SCI control register 1 (SCC1)
SCI control register 2 (SCC2)
SCI control register 3 (SCC3)
SCI status register 1 (SCS1)
SCI status register 2 (SCS2)
SCI data register (SCDR)
SCI baud rate register (SCBR)
Enables loop mode operation
Enables the SCI
Controls output polarity
Controls character length
Controls SCI wakeup method
Controls idle character detection
Enables parity function
Controls parity type
Address:
Setting the TXINV bit inverts all transmitted values, including idle, break,
start, and stop bits.
Reset:
Read:
Write:
LOOPS
$0013
Bit 7
0
Figure 13-10. SCI Control Register 1 (SCC1)
ENSCI
6
0
MC68HC908GR8B Data Sheet, Rev. 3.0
TXINV
5
0
NOTE
M
4
0
WAKE
3
0
ILTY
2
0
PEN
1
0
Freescale Semiconductor
Bit 0
PTY
0