MC68HC908GP32CB Freescale Semiconductor, MC68HC908GP32CB Datasheet - Page 141

• Manufacturer Part Number: MC68HC908GP32CB
• Description: IC MCU 32K FLASH 8MHZ 42-SDIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GP32CB

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 33
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 42-DIP (0.600", 15.24mm)
• For Use With: M68EVB908GP32 - BOARD EVALUATION FOR HC908GP32
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

error occurs. In most applications, the baud rate tolerance is much more than the degree of misalignment
that is likely to occur.
As the receiver samples an incoming character, it resynchronizes the RT clock on any valid falling edge
within the character. Resynchronization within characters corrects misalignments between transmitter bit
times and receiver bit times.
Slow Data Tolerance
Figure 13-7
or a framing error. The slow stop bit begins at RT8 instead of RT1 but arrives in time 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
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
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
Freescale Semiconductor
shows how much a slow received character can be misaligned without causing a noise error
RECEIVER
RT CLOCK
MSB
MC68HC908GP32 Data Sheet, Rev. 10
154 147
------------------------- -
170 163
------------------------- -
Figure
Figure
Figure 13-7. Slow Data
154
170
–
–
13-7, the receiver counts 154 RT cycles at the point when
13-7, the receiver counts 170 RT cycles at the point when
×
×
100
100
SAMPLES
DATA
=
=
4.54%
4.12%
STOP
Functional Description
141