MC9S08QE16CLC Datasheet, PDF (225/350 Pages) Freescale Semiconductor, Inc – Low-power wireless applications, Gas, water and heater meters

Field
2
RE
1
RWU
0
SBK
Serial Communications Interface (S08SCIV4)
Table 13-4. SCIxC2 Field Descriptions (continued)
Description
Receiver Enable — When the SCI receiver is off, the RxD pin reverts to being a general-purpose port I/O pin. If
LOOPS = 1 the RxD pin reverts to being a general-purpose I/O pin even if RE = 1.
0 Receiver off.
1 Receiver on.
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 13.3.3.2, “Receiver Wakeup Operation” for more details.
0 Normal SCI receiver operation.
1 SCI receiver in standby waiting for wakeup condition.
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 (13 or 14 if BRK13 = 1) 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 13.3.2.1, “Send Break and
Queued Idle” for more details.
0 Normal transmitter operation.
1 Queue break character(s) to be sent.
13.2.4 SCI Status Register 1 (SCIxS1)
This register has eight read-only status flags. Writes have no effect. Special software sequences (which do
not involve writing to this register) are used to clear these status flags.
7
6
5
4
3
2
1
0
R TDRE
TC
RDRF
IDLE
OR
NF
FE
PF
W
Reset
1
1
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 13-8. SCI Status Register 1 (SCIxS1)
MC9S08AC60 Series Data Sheet, Rev. 3
Freescale Semiconductor
225