MC68HC908KX8 Datasheet, PDF (247/310 Pages) Motorola, Inc – Microcontrollers

Analog-to-Digital Converter (ADC)
Functional Description
INTERNAL
DATA BUS
READ DDRB
WRITE
WRITE PTB
RESET
READ PTB
DDRBx
PTBx
READ ADR
ADC DATA REGISTER
DISABLE
PTBx
ADC CHANNEL x
DISABLE
CONVERSION
INTERRUPT ^COMPLETE
ADC
LOGIC
ADC VOLTAGE IN
ADCVIN
ADCH[4:0]
CHANNEL
SELECT
AIEN COCO
CGMXCLK
BUS CLOCK
ADC CLOCK
CLOCK
GENERATOR
ADIV[2:0] ADICLK
Figure 17-1. ADC Block Diagram
17.4.2 Voltage Conversion
NOTE:
When the input voltage to the ADC equals V_REFH (see 20.10 Trimmed
Accuracy of the Internal Clock Generator), the ADC converts the
signal to $FF (full scale). If the input voltage equals V_SS, the ADC
converts it to $00. Input voltages between V_REFH and V_SS are a straight-
line linear conversion. All other input voltages will result in $FF if greater
than V_REFH and $00 if less than V_SS.
Input voltage should not exceed the high-voltage reference, which in turn
should not exceed supply voltages.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 — Rev. 1.0
MOTOROLA
Analog-to-Digital Converter (ADC)
Technical Data
247