mc68hc908lb8 Freescale Semiconductor, Inc, mc68hc908lb8 Datasheet - Page 49

• Manufacturer Part Number: mc68hc908lb8
• Description: M68hc08 Microcontrollers Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

AIEN — ADC Interrupt Enable Bit
ADCO — ADC Continuous Conversion Bit
ADCH4–ADCH0 — ADC Channel Select Bits
The voltage levels supplied from internal reference nodes, as specified in
Table
applications.
Freescale Semiconductor
When this bit is set, an interrupt is generated at the end of an ADC conversion. The interrupt signal is
cleared when the data register is read or the status/control register is written. Reset clears the AIEN bit.
When set, the ADC will convert samples continuously and update the ADR register at the end of each
conversion. Only one conversion is completed between writes to the ADSCR when this bit is cleared.
Reset clears the ADCO bit.
ADCH4–ADCH0 form a 5-bit field which is used to select one of 7 ADC channels. Only seven channels,
AD6–AD0, are available on this MCU. The channels are detailed in
when using a port pin as both an analog and digital input simultaneously to prevent switching noise
from corrupting the analog signal. See
The ADC subsystem is turned off when the channel select bits are all set to 1. This feature allows for
reduced power consumption for the MCU when the ADC is not being used.
1 = Conversion completed (AIEN = 0)
0 = Conversion not completed (AIEN = 0)/CPU interrupt (AIEN = 1)
1 = ADC interrupt enabled
0 = ADC interrupt disabled
1 = Continuous ADC conversion
0 = One ADC conversion
3-1, are used to verify the operation of the ADC converter both in production test and for user
Recovery from the disabled state requires one conversion cycle to stabilize.
ADCH4
0
0
0
0
0
0
0
0
↓
1
1
1
1
ADCH3
↓
0
0
0
0
0
0
0
1
1
1
1
1
Table 3-1. Mux Channel Select
MC68HC908LB8 Data Sheet, Rev. 1
ADCH2
0
0
0
0
1
1
1
0
↓
1
1
1
1
Table
3-1.
ADCH1
NOTE
↓
0
0
1
1
0
0
1
0
0
0
1
1
ADCH0
0
1
0
1
0
1
0
0
↓
0
1
0
1
(1)
Table
ADC power off
Input Select
PTB7/AD6
PTA0/AD0
PTA1/AD1
PTA2/AD2
PTA3/AD3
PTA4/AD4
PTA6/AD5
V
V
Unused
3-1. Care should be taken
REFH
REFL
(2)
(2)
I/O Registers
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