MC68HC08AZ60ACFU MOTOROLA [Motorola, Inc], MC68HC08AZ60ACFU Datasheet - Page 436

• Manufacturer Part Number: MC68HC08AZ60ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

Analog-to-Digital Converter (ADC-15)
24.4.2 Voltage Conversion
24.4.3 Conversion Time
Advance Information
436
NOTE:
NOTE:
ADC will return a logic 0 if the corresponding DDR bit is at logic 0. If the
DDR bit is at logic 1, the value in the port data latch is read.
Do not use ADC channels ATD14 or ATD12 when using the
PTD6/ATD14/TACLK or PTD4/ATD12/TBCLK pins as the clock inputs
for the 16-bit Timers.
When the input voltage to the ADC equals V
Specifications
scale). If the input voltage equals AV
$00. Input voltages between V
linear conversion. Conversion accuracy of all other input voltages is not
guaranteed. Avoid current injection on unused ADC inputs to prevent
potential conversion error.
Input voltage should not exceed the analog supply voltages.
Conversion starts after a write to the ADSCR (ADC status control
register, $0038), and requires between 16 and 17 ADC clock cycles to
complete. Conversion time in terms of the number of bus cycles is a
function of ADICLK select, CGMXCLK frequency, bus frequency, and
ADIV prescaler bits. For example, with a CGMXCLK frequency of 4
MHz, bus frequency of 8 MHz, and fixed ADC clock frequency of 1 MHz,
one conversion will take between 16 and 17 s and there will be between
128 bus cycles between each conversion. Sample rate is approximately
60 kHz.
Refer to
Number of Bus Cycles = Conversion Time x Bus Frequency
Conversion Time =
Analog-to-Digital Converter (ADC-15)
Electrical Specifications
on page 445), the ADC converts the signal to $FF (full
16 to 17 ADC Clock Cycles
ADC Clock Frequency
REFH
on page 445.
and AV
SS
/V
REFL,
SS/
REFH
MC68HC08AZ60A — Rev 0.0
V
the ADC converts it to
REFL
(see
are a straight-line
Electrical
MOTOROLA