Rainbow Electronics ATmega64L - Manual (Page 213)

213
ATmega16(L)
2466B–09/01
Special FunctionIO Register –
SFIOR
• Bit 7:5 - 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 trigger 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 trig-
ger event, even if the ADC Interrupt Flag is set
.
• Bit 4 - ADHSM: ADC High Speed Mode
Writing this bit to one enables the ADC High Speed Mode. This mode enables higher
conversion rate at the expense of higher power consumption.
Bit 7 6 5 4 3 2 1 0
ADTS2 ADTS1 ADTS0 ADH-
SM
ACME PUD PSR2 PSR10 SFIOR
Read/Write R/W R/W R/W R/W R/W R/W R/W R/W
Initial Value 0 0 0 0 0 0 0 0
Table 85. 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/Counter Compare Match B
1 1 0 Timer/Counter1 Overflow
1 1 1 Timer/Counter1 Capture Event