s908ab32ag0cfue Freescale Semiconductor, Inc, s908ab32ag0cfue Datasheet - Page 252

• Manufacturer Part Number: s908ab32ag0cfue
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Serial Communications Interface
15.5.3.3 Data Sampling
Technical Data
252
RT CLOCK
RT CLOCK
SAMPLES
PTE1/RxD
CLOCK
RESET
STATE
RT
The receiver samples the PTE1/RxD pin at the RT clock rate. The RT
clock is an internal signal with a frequency 16 times the baud rate. To
adjust for baud rate mismatch, the RT clock is resynchronized at the
following times (see
To locate the start bit, data recovery logic does an asynchronous search
for a logic 0 preceded by three logic 1s. When the falling edge of a
possible start bit occurs, the RT clock begins to count to 16.
•
•
QUALIFICATION
Figure 15-6. Receiver Data Sampling
Serial Communications Interface Module (SCI)
START BIT
After every start bit
After the receiver detects a data bit change from logic 1 to logic 0
(after the majority of data bit samples at RT8, RT9, and RT10
returns a valid logic 1 and the majority of the next RT8, RT9, and
RT10 samples returns a valid logic 0)
VERIFICATION
Figure
START BIT
15-6):
START BIT
SAMPLING
DATA
MC68HC908AB32
Freescale Semiconductor
LSB
—
Rev. 1.1