MC68HC908GT8CFB Freescale Semiconductor, MC68HC908GT8CFB Datasheet - Page 56

• Manufacturer Part Number: MC68HC908GT8CFB
• Description: IC MCU 8K FLASH 8MHZ 44-QFP
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC68HC908GT8CFB

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI, SPI
• Peripherals: LVD, POR, PWM
• Number Of I /o: 34
• Program Memory Size: 8KB (8K 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: 44-QFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

Analog-to-Digital Converter (ADC)
3.7.3 ADC Clock Register
The ADC clock register (ADCLK) selects the clock frequency for the ADC.
ADIV2–ADIV0 — ADC Clock Prescaler Bits
ADICLK — ADC Input Clock Select Bit
The ADC requires a clock rate of approximately 1 MHz for correct operation. If the selected clock source
is not fast enough, the ADC will generate incorrect conversions. See
56
ADIV2–ADIV0 form a 3-bit field which selects the divide ratio used by the ADC to generate the internal
ADC clock.
approximately 1 MHz.
ADICLK selects either the bus clock or the oscillator output clock (CGMXCLK) as the input clock
source to generate the internal ADC clock. Reset selects CGMXCLK as the ADC clock source.
1 = Internal bus clock
0 = Oscillator output clock (CGMXCLK)
Address:
Table 3-2
Reset:
Read:
Write:
MC68HC908GT16 • MC68HC908GT8 • MC68HC08GT16 Data Sheet, Rev. 5.0
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ADIV2
Bit 7
1. X = Don’t care
0
shows the available clock configurations. The ADC clock should be set to
ADIV2
0
0
0
0
1
f
ADIC
Figure 3-5. ADC Clock Register (ADCLK)
= Unimplemented
ADIV1
6
0
Table 3-2. ADC Clock Divide Ratio
=
ADIV1
X
f
0
0
1
1
(1)
CGMXCLK
ADIV0
5
0
ADIV[2:0]
ADIV0
X
or bus frequency
0
1
0
1
(1)
ADICLK
4
0
ADC input clock ÷ 1
ADC input clock ÷ 2
ADC input clock ÷ 4
ADC input clock ÷ 8
ADC input clock ÷ 16
3
0
0
ADC Clock Rate
≅ 1 MHz
20.16 ADC
2
0
0
1
0
0
Characteristics.
Freescale Semiconductor
Bit 0
0
0