mc68hc908gp20 Freescale Semiconductor, Inc, mc68hc908gp20 Datasheet - Page 89

• Manufacturer Part Number: mc68hc908gp20
• Description: M68hc08 Family Of 8-bit Microcontroller Units Mcus
• Manufacturer: Freescale Semiconductor, Inc

5.4.1 ADC Port I/O Pins
MC68HC908GP20
Freescale Semiconductor
—
Rev 2.1
PTB7/AD7–PTB0/AD0 are general-purpose I/O (input/output) pins
ADC channel/port pin will be used as the input signal. The ADC
overrides the port I/O logic by forcing that pin as input to the ADC. The
remaining ADC channels/port pins are controlled by the port I/O logic
and can be used as general-purpose I/O. Writes to the port register or
DDR will not have any affect on the port pin that is selected by the ADC.
Read of a port pin in use by the ADC will return a logic 0.
DATA BUS
INTERNAL
AIEN
that share with the ADC channels. The channel select bits define which
INTERRUPT
LOGIC
READ DDRB/DDRB
WRITE DDRB/DDRD
WRITE PTB
READ PTB
COCO
BUS CLOCK
CONVERSION
COMPLETE
CGMXCLK
RESET
ADIV2–ADIV0
Figure 5-1. ADC Block Diagram
ADC DATA REGISTER
GENERATOR
DDRBx
PTBx
CLOCK
ADC
ADC CLOCK
ADICLK
VOLTAGE IN
(ADV
ADC
IN
DISABLE
)
DISABLE
CHANNEL
SELECT
Advance Information
ADC CHANNEL x
PTB/Dx
ADCH4–ADCH0
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