MC68HC908LJ12 Datasheet, PDF (303/413 Pages) Freescale Semiconductor, Inc – 8-bit microcontroller units

Analog-to-Digital Converter (ADC)
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.
INTERNAL
DATA BUS
READ DDRAx/DDRBx
WRITE DDRAx/DDRBx
RESET
WRITE PTAx/PTBx
DDRAx/DDRBx
PTAx/PTBx
DISABLE
READ PTAx/PTBx
DISABLE
ADC DATA REGISTERS
ADRH ADRL
ADC0–ADC5
(6 CHANNELS)
INTERRUPT
LOGIC
CONVERSION
COMPLETE
ADC
ADC
VOLTAGE IN
(V_ADIN)
CHANNEL
SELECT
PTAx/PTBx
V_REFH
V_REFL
1.2 V
BANDGAP
REFERENCE
AIEN COCO
CGMXCLK
BUS CLOCK
ADC CLOCK
CLOCK
GENERATOR
ADCH[4:0]
ADIV[2:0] ADICLK
Figure 15-2. ADC Block Diagram
Technical Data
304
Analog-to-Digital Converter (ADC)
MC68HC908LJ12 — Rev. 2.1
Freescale Semiconductor