Rainbow Electronics ATmega128RFA1 - Manual (Page 430)

430
8266A-MCU Wireless-12/09
ATmega128RFA1
MUX5:0
Single Ended
Input
Positive Differential
Input
Negative Differential
Input Gain
101111 Reserved
110000 Reserved
110001 Reserved
110010 Reserved
110011 Reserved
110100 SRAM Back-bias Voltage V
DRTBBP
110101 Reserved
110110 Reserved
110111
N/A
Reserved
111000 Reserved
111001 Reserved
111010 Reserved
111011 Reserved
111100 Reserved
111101
N/A
SRAM Back-bias Voltage V
DRTBBN
111110 Reserved
111111 Reserved
N/A
• Bits 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 A/D 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 (ADTS2:0=0) will not cause a
trigger event, even if the ADC Interrupt Flag is set.
Table 27-12. 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 A
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
27.11.3 ADCSRA – ADC Control and Status Register A
Bit 7 6 5 4 3 2 1 0
NA ($7A) ADEN ADSC ADATE ADIF ADIE ADPS2 ADPS1 ADPS0 ADCSRA
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