Datasheet

290
7682C–AUTO–04/08
AT90CAN32/64/128
• ADC9:0: ADC Conversion Result
These bits represent the result from the conversion, as detailed in “ADC Conversion Result” on
page 283.
21.8.4 ADC Control and Status Register B – ADCSRB
• Bit 7– Reserved Bit
This bit is reserved for future use. For compatibility with future devices, it must be written to zero
when ADCSRB is written.
• Bit 5:3– Reserved Bits
These bits are reserved for future use. For compatibility with future devices, they must be written
to zero when ADCSRB is written.
• Bit 2:0 – ADTS2:0: ADC Auto Trigger Source
If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger
an ADC conversion. If ADATE is cleared, the ADTS2:0 settings will have no effect. A conversion
will be triggered by the rising edge of the selected interrupt flag. Note that switching from a trig-
ger source that is cleared to a trigger source that is set, will generate a positive edge on the
trigger signal. If ADEN in ADCSRA is set, this will start a conversion. Switching to Free Running
mode (ADTS[2:0]=0) will not cause a trigger event, even if the ADC Interrupt Flag is set
.
Bit 7 6 5 4 3 2 1 0
– ACME – – – ADTS2 ADTS1 ADTS0 ADCSRB
Read/Write R R/W R R R R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Table 21-6. ADC Auto Trigger Source Selections
ADTS2 ADTS1 ADTS0 Trigger Source
0 0 0 Free Running mode
0 0 1 Analog Comparator
0 1 0 External Interrupt Request 0
0 1 1 Timer/Counter0 Compare Match
1 0 0 Timer/Counter0 Overflow
1 0 1 Timer/Counter1 Compare Match B
1 1 0 Timer/Counter1 Overflow
1 1 1 Timer/Counter1 Capture Event