Datasheet

Analog-to-Digital Converter (ADC)
Technical Data MC68HC908LJ12 — Rev. 2.1
304 Analog-to-Digital Converter (ADC) Freescale Semiconductor
logic and can be used as general-purpose I/O pins. Writes to the port
data register or data direction register will not have any affect on the port
pin that is selected by the ADC. Read of a port pin which is in use by the
ADC will return the pin condition 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.
Figure 15-2. ADC Block Diagram
ADC DATA REGISTERS
INTERNAL
DATA BUS
READ DDRAx/DDRBx
WRITE DDRAx/DDRBx
RESET
WRITE PTAx/PTBx
READ PTAx/PTBx
PTAx/PTBx
DDRAx/DDRBx
PTAx/PTBx
INTERRUPT
LOGIC
CHANNEL
SELECT
ADC
CLOCK
GENERATOR
CONVERSION
COMPLETE
ADC
(V
ADIN
)
ADC CLOCK
CGMXCLK
BUS CLOCK
DISABLE
DISABLE
(6 CHANNELS)
ADIV[2:0] ADICLK
VOLTAGE IN
V
REFL
V
REFH
ADCH[4:0]
ADC0–ADC5
COCOAIEN
ADRH
ADRL
1.2V
BANDGAP
REFERENCE