mc68hc908mr32 Freescale Semiconductor, Inc, mc68hc908mr32 Datasheet - Page 169

• Manufacturer Part Number: mc68hc908mr32
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

13.6.2 PTF4/RxD (Receive Data)
The PTF4/RxD pin is the serial data input to the SCI receiver. The SCI shares the PTF4/RxD pin with
port F. When the SCI is enabled, the PTF4/RxD pin is an input regardless of the state of the DDRF4 bit
in data direction register F (DDRF).
13.7 I/O Registers
These I/O registers control and monitor SCI operation:
13.7.1 SCI Control Register 1
SCI control register 1 (SCC1):
LOOPS — Loop Mode Select Bit
Freescale Semiconductor
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
This read/write bit enables loop mode operation. In loop mode the PTF4/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.
1 = Loop mode enabled
0 = Normal operation enabled
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: $0038
Reset:
Read:
Write:
LOOPS
Bit 7
0
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Figure 13-8. SCI Control Register 1 (SCC1)
ENSCI
6
0
TXINV
5
0
M
4
0
WAKE
3
0
ILTY
2
0
PEN
1
0
Bit 0
PTY
0
I/O Registers
169