MC68HC908AB32 MOTOROLA [Motorola, Inc], MC68HC908AB32 Datasheet - Page 257

• Manufacturer Part Number: MC68HC908AB32
• Description: HCMOS Microcontroller Unit
• Manufacturer: MOTOROLA [Motorola, Inc]

15.5.3.6 Receiver Wakeup
MC68HC908AB32
MOTOROLA
—
Rev. 1.0
For a 9-bit character, data sampling of the stop bit takes the receiver
10 bit times
With the misaligned character shown in
170 RT cycles at the point when the count of the transmitting device is
11 bit times
The maximum percent difference between the receiver count and the
transmitter count of a fast 9-bit character with no errors is
So that the MCU can ignore transmissions intended only for other
receivers in multiple-receiver systems, the receiver can be put into a
standby state. Setting the receiver wakeup bit, RWU, in SCC2 puts the
receiver into a standby state during which receiver interrupts are
disabled.
Depending on the state of the WAKE bit in SCC1, either of two
conditions on the PTE1/RxD pin can bring the receiver out of the standby
state:
•
•
Freescale Semiconductor, Inc.
Serial Communications Interface Module (SCI)
For More Information On This Product,
Address mark — An address mark is a logic 1 in the most
significant bit position of a received character. When the WAKE bit
is set, an address mark wakes the receiver from the standby state
by clearing the RWU bit. The address mark also sets the SCI
receiver full bit, SCRF. Software can then compare the character
containing the address mark to the user-defined address of the
receiver. If they are the same, the receiver remains awake and
processes the characters that follow. If they are not the same,
software can set the RWU bit and put the receiver back into the
standby state.
Idle input line condition — When the WAKE bit is clear, an idle
character on the PTE1/RxD pin wakes the receiver from the
standby state by clearing the RWU bit. The idle character that
wakes the receiver does not set the receiver idle bit, IDLE, or the
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16 RT cycles + 10 RT cycles = 170 RT cycles.
16 RT cycles = 176 RT cycles.
170 176
------------------------- -
170
–
Serial Communications Interface Module (SCI)
100
Figure
=
3.53%
15-8, the receiver counts
Functional Description
Technical Data
257