mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 231

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

17.5.2.5 Inversion of Transmitted Output
17.5.2.6 Transmitter Interrupts
MC68HC908AS60 — Rev. 1.0
NOTE:
If the TE bit is cleared during a transmission, the TxD pin becomes idle
after completion of the transmission in progress. Clearing and then
setting the TE bit during a transmission queues an idle character to be
sent after the character currently being transmitted.
When queueing an idle character, return the TE bit to logic 1 before the
stop bit of the current character shifts out to the TxD pin. Setting TE after
the stop bit appears on TxD causes data previously written to the SCDR
to be lost.
A good time to toggle the TE bit for a queued idle character is when the
SCTE bit becomes set and just before writing the next byte to the SCDR.
The transmit inversion bit (TXINV) in SCI control register 1 (SCC1)
reverses the polarity of transmitted data. All transmitted values, including
idle, break, start, and stop bits, are inverted when TXINV is at logic 1.
See
These conditions can generate CPU interrupt requests from the SCI
transmitter:
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Freescale Semiconductor, Inc.
17.9.1 SCI Control Register
For More Information On This Product,
SCI transmitter empty (SCTE) — The SCTE bit in SCS1 indicates
that the SCDR has transferred a character to the transmit shift
register. SCTE can generate a transmitter CPU interrupt request.
Setting the SCI transmit interrupt enable bit, SCTIE, in SCC2
enables the SCTE bit to generate transmitter CPU interrupt
requests.
Transmission complete (TC) — The TC bit in SCS1 indicates that
the transmit shift register and the SCDR are empty and that no
break or idle character has been generated. The transmission
complete interrupt enable bit, TCIE, in SCC2 enables the TC bit to
generate transmitter CPU interrupt requests.
Serial Communications Interface (SCI)
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1.
Serial Communications Interface (SCI)
Functional Description
Technical Data