MCU Serial Communications Interface (SCI)
MC1321x Reference Manual, Rev. 1.6
18-12
Freescale Semiconductor
TE — Transmitter Enable
1 = Transmitter on.
0 = Transmitter off.
TE must be 1 in order to use the SCI transmitter. Normally, when TE = 1, the SCI forces the TxD1 pin
to act as an output for the SCI system. If LOOPS = 1 and RSRC = 0, the TxD1 pin reverts to being a
port B general-purpose I/O pin even if TE = 1.
When the SCI is configured for single-wire operation (LOOPS = RSRC = 1), TXDIR controls the
direction of traffic on the single SCI communication line (TxD1 pin).
TE also can be used to queue an idle character by writing TE = 0 then TE = 1 while a transmission is
in progress. Refer to
Section 18.4.2, “Send Break and Queued Idle”
for more details.
When TE is written to 0, the transmitter keeps control of the port TxD1 pin until any data, queued idle,
or queued break character finishes transmitting before allowing the pin to revert to a general-purpose
I/O pin.
RE — Receiver Enable
When the SCI receiver is off, the RxD1 pin reverts to being a general-purpose port I/O pin.
1 = Receiver on.
0 = Receiver off.
RWU — Receiver Wakeup Control
This bit can be written to 1 to place the SCI receiver in a standby state where it waits for automatic
hardware detection of a selected wakeup condition. The wakeup condition is either an idle line between
messages (WAKE = 0, idle-line wakeup), or a logic 1 in the most significant data bit in a character
(WAKE = 1, address-mark wakeup). Application software sets RWU and (normally) a selected
hardware condition automatically clears RWU. Refer to
Section 18.5.3, “Receiver Wakeup
for more details.
1 = SCI receiver in standby waiting for wakeup condition.
0 = Normal SCI receiver operation.
SBK — Send Break
Writing a 1 and then a 0 to SBK queues a break character in the transmit data stream. Additional break
characters of 10 or 11 bit times of logic 0 are queued as long as SBK = 1. Depending on the timing of
the set and clear of SBK relative to the information currently being transmitted, a second break
character may be queued before software clears SBK. Refer to
Section 18.4.2, “Send Break and
,
for more details.
1 = Queue break character(s) to be sent.
0 = Normal transmitter operation.
Summary of Contents for freescale semiconductor MC13211
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Page 166: ...Modem Modes of Operation MC1321x Reference Manual Rev 1 6 7 22 Freescale Semiconductor...
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Page 186: ...MCU Modes of Operation MC1321x Reference Manual Rev 1 6 10 8 Freescale Semiconductor...
Page 208: ...MCU Memory MC1321x Reference Manual Rev 1 6 11 22 Freescale Semiconductor...
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Page 288: ...MCU Central Processor Unit CPU MC1321x Reference Manual Rev 1 6 15 20 Freescale Semiconductor...
Page 308: ...MCU Timer PWM TPM Module MC1321x Reference Manual Rev 1 6 17 16 Freescale Semiconductor...
Page 338: ...Inter Integrated Circuit IIC MC1321x Reference Manual Rev 1 6 19 14 Freescale Semiconductor...
Page 372: ...Development Support MC1321x Reference Manual Rev 1 6 21 20 Freescale Semiconductor...
