mc68hc908kx8 Freescale Semiconductor, Inc, mc68hc908kx8 Datasheet - Page 122

• Manufacturer Part Number: mc68hc908kx8
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Serial Communications Interface Module (SCI)
Fast Data Tolerance
122
With the misaligned character shown in
when the count of the transmitting device is 9 bit times × 16 RT cycles + 3 RT cycles = 147 RT cycles.
The maximum percent difference between the receiver count and the transmitter count of a slow 8-bit
character with no errors is
For a 9-bit character, data sampling of the stop bit takes the receiver
10 bit times × 16 RT cycles + 10 RT cycles = 170 RT cycles.
With the misaligned character shown in
when the count of the transmitting device is
10 bit times × 16 RT cycles + 3 RT cycles = 163 RT cycles.
The maximum percent difference between the receiver count and the transmitter count of a slow 9-bit
character with no errors is
Figure 12-9
error or a framing error. The fast stop bit ends at RT10 instead of RT16 but is still there for the stop bit
data samples at RT8, RT9, and RT10.
For an 8-bit character, data sampling of the stop bit takes the receiver
9 bit times × 16 RT cycles + 10 RT cycles = 154 RT cycles.
With the misaligned character shown in
when the count of the transmitting device is 10 bit times × 16 RT cycles = 160 RT cycles.
The maximum percent difference between the receiver count and the transmitter count of a fast 8-bit
character with no errors is
For a 9-bit character, data sampling of the stop bit takes the receiver
10 bit times × 16 RT cycles + 10 RT cycles = 170 RT cycles.
With the misaligned character shown in
when the count of the transmitting device is 11 bit times × 16 RT cycles = 176 RT cycles.
shows how much a fast received character can be misaligned without causing a noise
RECEIVER
RT CLOCK
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
154 160
------------------------- -
154 147
------------------------- -
170 163
------------------------- -
Figure 12-9. Fast Data
154
154
170
STOP
–
Figure
Figure
Figure
Figure
–
–
×
×
×
12-8, the receiver counts 154 RT cycles at the point
12-8, the receiver counts 170 RT cycles at the point
12-9, the receiver counts 154 RT cycles at the point
12-9, the receiver counts 170 RT cycles at the point
100
100
100
SAMPLES
DATA
=
=
=
3.90%.
4.54%
4.12%
IDLE OR NEXT CHARACTER
Freescale Semiconductor