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Serial Communications Interface (SCI)
SCI I/O Registers
MC68HC705C8A — Rev. 3
Technical Data
MOTOROLA
Serial Communications Interface (SCI)
idle input or an address mark brings the receiver out of the standby
state. Reset clears the RWU bit.
1 = Standby state
0 = Normal operation
SBK — Send Break Bit
Setting this read/write bit continuously transmits break codes in the
form of 10-bit or 11-bit groups of logic 0s. Clearing the SBK bit stops
the break codes and transmits a logic 1 as a start bit. Reset clears the
SBK bit.
1 = Break codes being transmitted
0 = No break codes being transmitted
10.6.4 SCI Status Register
The SCI status register (SCSR) shown in Figure 10-8 contains flags to
signal these conditions:
Transfer of SCDR data to transmit shift register complete
Transmission complete
Transfer of receive shift register data to SCDR complete
Receiver input idle
Receiver overrun
Noisy data
Framing error
Address:
$0010
Bit 7
6
54321
Bit 0
Read:
TDRE
TC
RDRF
IDLE
OR
NF
FE
Write:
Reset:
11
00000
U
= Unimplemented
U = Unaffected
Figure 10-8. SCI Status Register (SCSR)
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Freescale Semiconductor, Inc.
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