MC68HC908QL4 Datasheet, PDF (139/226 Pages) Motorola, Inc – Microcontrollers

I/O Signals
14.7 I/O Signals
The SLIC module can share its two pins with the general-purpose I/O pins. See Figure 14-1 for the port
pins that are shared.
14.7.1 SLCTX — SLIC Transmit Pin
The SLCTX pin serves as the serial output of the SLIC module.
14.7.2 SLCRX — SLIC Receive Pin
The SLCRX pin serves as the serial input of the SLIC module. This input feeds directly into the digital
receive filter block which filters out noise glitches from the incoming data stream.
14.8 Registers
14.8.1 SLIC Control Register 1
SLIC control register 1 (SLCC1) contains bits used to control various basic features of the SLIC module,
including features used for initialization and at runtime.
Read:
Write:
Reset:
Bit 7
6
5
4
3
2
1
0
0
0
INITREQ
WAKETX TXABRT IMSG
0
0
1
0
0
0
0
= Unimplemented
Figure 14-4. SLIC Control Register 1 (SLCC1)
Bit 0
SLCIE
0
INITREQ —Initialization Request
Requesting initialization mode by setting this bit will place the SLIC module into its initialized state
immediately. If transmission or reception of data is in progress, the transaction will be terminated
immediately upon entry into initialization mode (signified by INITACK being set to 1). To return to
normal SLIC operation after the SLIC has been initialized (the INITACK is high), the INITREQ must be
cleared by software.
1 = Request for SLIC to be put into reset state immediately
0 = Normal operation
WAKETX — Transmit Wakeup Symbol
This bit allows the user to transmit a wakeup symbol on the LIN bus. When set, this sends a wakeup
symbol, as defined in the LIN specification a single time, then resets to 0. This bit will read 1 while the
wakeup symbol is being transmitted on the bus. This bit will be automatically cleared when the wakeup
symbol is complete.
1 = Send wakeup symbol on LIN bus
0 = Normal operation
TXABRT — Transmit Abort Message
1 = Transmitter aborts current transmission at next byte boundary; TXABRT resets to 0 after the
transmission is successfully aborted
0 = Normal operation
MC68HC908QL4 Data Sheet, Rev. 7
Freescale Semiconductor
139