at90ls4433 ATMEL Corporation, at90ls4433 Datasheet - Page 67

• Manufacturer Part Number: at90ls4433
• Description: At90s4433 8-bit Avr Microcontroller With 4k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

ADC Noise Canceler
Function
1042H–AVR–04/03
Figure 47. ADC Timing Diagram, Single Conversion
Figure 48. ADC Timing Diagram, Free Run Conversion
The ADC features a Noise Canceler that enables conversion during Idle mode to reduce
noise induced from the CPU core. To make use of this feature, the following procedure
should be used:
1. Make sure that the ADC is enabled and is not busy converting. Single Conver-
2. Enter Idle mode. The ADC will start a conversion once the CPU has been halted.
3. If no other interrupts occur before the ADC conversion completes, the ADC inter-
Cycle Number
ADC Clock
ADSC
ADIF
ADCH
ADCL
sion mode must be selected and the ADC conversion complete interrupt must be
enabled. Thus:
ADEN = 1
ADSC = 0
ADFR = 0
ADIE = 1
rupt will wake up the MCU and execute the ADC conversion complete interrupt
routine.
1
Cycle Number
ADC Clock
ADSC
Hold Strobe
ADIF
ADCH
ADCL
2
MUX and REFS
Update
3
Sample & Hold
4
5
One Conversion
11
6
7
12
One Conversion
8
13
9
Next
Conversion
10
Conversion
1
MSB of Result
LSB of Result
complete
11
2
AT90S/LS4433
12
13
Sign and MSB of Result
LSB of Result
Next Conversion
1
2
MUX and REFS
Update
3
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