DEMO9S08EL32 Freescale Semiconductor, DEMO9S08EL32 Datasheet - Page 138

• Manufacturer Part Number: DEMO9S08EL32
• Description: BOARD DEMO FOR 9S08 EL MCU
• Manufacturer: Freescale Semiconductor
• Type: MCUr

Specifications of DEMO9S08EL32

• Contents: Evaluation Board
• Processor To Be Evaluated: MC9S08EL32
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Operating Supply Voltage: 12 V
• Silicon Manufacturer: Freescale
• Core Architecture: HCS08
• Core Sub-architecture: HCS08
• Silicon Core Number: MC9S08
• Silicon Family Name: S08EL
• Rohs Compliant: Yes
• For Use With/related Products: MC9S08EL32
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Chapter 10 Analog-to-Digital Converter (S08ADCV1)
10.1.2
The ADC module is capable of performing conversions using the MCU bus clock, the bus clock divided
by two, the local asynchronous clock (ADACK) within the module, or the alternate clock, ALTCLK. The
alternate clock for the MC9S08EL32 Series and MC9S08SL16 Series MCU devices is the external
reference clock (ICSERCLK).
The selected clock source must run at a frequency such that the ADC conversion clock (ADCK) runs at a
frequency within its specified range (f
determined by the ADIV bits.
ALTCLK is active while the MCU is in wait mode provided the conditions described above are met. This
allows ALTCLK to be used as the conversion clock source for the ADC while the MCU is in wait mode.
ALTCLK cannot be used as the ADC conversion clock source while the MCU is in either stop2 or stop3.
10.1.3
The ADC hardware trigger, ADHWT, is the output from the real time counter (RTC) overflow. The RTC
can be configured to cause a hardware trigger in MCU run, wait, and stop3 modes.
10.1.4
The ADC module includes a temperature sensor whose output is connected to AD26.
provides an approximate transfer function of the temperature sensor.
where:
For temperature calculations, use the V
In application code, the user reads the temperature sensor channel, calculates V
V
less than V
138
TEMP25
— V
— V
— m is the hot or cold voltage versus temperature slope in V/°C.
. If V
TEMP25
Alternate Clock
Hardware Trigger
Temperature Sensor
TEMP
TEMP25
TEMP
is the voltage of the temperature sensor channel at the ambient temperature.
the hot slope value is applied in
is greater than V
is the voltage of the temperature sensor channel at 25°C.
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Temp = 25 - ((V
TEMP25
ADCK
TEMP25
) after being divided down from the ALTCLK input as
the cold slope value is applied in
TEMP
and m values from the ADC Electricals table.
-V
Equation
TEMP25
) ÷ m)
10-1.
Equation
TEMP
Freescale Semiconductor
, and compares to
Equation 10-1
10-1. If V
Eqn. 10-1
TEMP
is