MC68HC908LB8CPE Freescale Semiconductor, MC68HC908LB8CPE Datasheet - Page 95

• Manufacturer Part Number: MC68HC908LB8CPE
• Description: IC MCU 8K FLASH 8MHZ 20DIP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908LB8CPE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Peripherals: LVR, POR, PWM
• Number Of I /o: 18
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 7x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Connectivity: -

10.4.2 Frequency Dithering on the HRP
The HRP provides frequency dithering between two signals whose periods differ by one HRPCLK cycle.
When the HRP is supplied with an 8 MHz clock, the difference between the period values is 125 ns.
The HRP provides a programmable number of dithering steps, up to a maximum of 32 steps. This results
in a maximum frequency resolution of 125/32 = 3.906 ns when using an 8 MHz clock.
Figure 10-5
32 dithering steps are chosen. In this example, the Period signal is output for 25% of the time, i.e. 8 of the
32 steps, and the Period+1 signal is output for 75% of the time, i.e. 24 of the 32 steps.
Freescale Semiconductor
AVERAGE
SIGNAL
shows the relationship between the two dithering frequencies and the output frequency when
0
13 kHz
10
10 kHz
20
Figure 10-4. Dithering Waveforms
10 kHz
30
MC68HC908LB8 Data Sheet, Rev. 1
20 kHz
40
1 CYCLE
50
60
70
80
20 kHz
90
100
Functional Description
% CYCLE
t
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