Advance Information MC68HC908MR16/MC68HC908MR32 — Rev. 4.0
294 Serial Communications Interface Module (SCI) MOTOROLA
Serial Communications Interface Module (SCI)
WAKE — Wakeup Condition Bit
This read/write bit determines which condition wakes up the SCI: a
logic 1 (address mark) in the most significant bit (MSB) position of a
received character or an idle condition on the PTE6/RxD pin. Reset
clears the WAKE bit.
1 = Address mark wakeup
0 = Idle line wakeup
ILTY — Idle Line Type Bit
This read/write bit determines when the SCI starts counting logic 1s
as idle character bits. The counting begins either after the sta rt bit or
after the stop bit. If the count begins after the start bit, then a string of
logic 1s preceding the stop bit may cause f al se r eco gniti o n of a n i dle
character. Beginning the count after the stop bit avoids false idle
character recognition, but requires properly synchronized
transmissions. Reset clears the ILTY bit.
1 = Idle character bit count begins after stop bit.
0 = Idle character bit count begins after start bit.
PEN — Parity Enable Bit
This read/write bit enables the SCI parity function. See Table 14-4.
When enabled, the parity function inserts a parity bit in the most
significant bit position. See Figure 14-3. Reset clears the PEN bit.
1 = Parity function enabled
0 = Parity function disabled
PTY — Parity Bit
This read/write bit determines whether the SCI generates and checks
for odd parity or even parity. See Table 14-4. Reset clears the
PTY bit.
1 = Odd parity
0 = Even parity
NOTE: Changing the PTY bit in the middle of a transmission or reception can
generate a parity error.