18.11 Amplifier Control Registers
The configuration of the amplifiers are controlled via two dedicated registers AMP0CSR and AMP1CSR. Then the start of
conversion is done via the ADC control and status registers.
The conversion result is stored on ADCH and ADCL register which contain respectively the most significant bits and the less
significant bits.
18.11.1 Amplifier 0 control and status register – AMP0CSR
Bit
7
6
5
4
3
2
1
0
AMP0EN AMP0IS AMP0G1 AMP0G0 AMPCMP0 AMP0TS2 AMP0TS1 AMP0TS0 AMP0CSR
Read/Write
Initial Value
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
• Bit 7 – AMP0EN: Amplifier 0 Enable Bit
Set this bit to enable the amplifier 0.
Clear this bit to disable the amplifier 0.
Clearing this bit while a conversion is running will take effect at the end of the conversion.
Warning: Always clear AMP0TS0:1 when clearing AMP0EN.
• Bit 6 – AMP0IS: Amplifier 0 Input Shunt
Set this bit to short-circuit the amplifier 0 input.
Clear this bit to normally use the amplifier 0.
• Bit 5, 4 – AMP0G1, 0: Amplifier 0 Gain Selection Bits
These 2 bits determine the gain of the amplifier 0.
The different setting are shown in Table 18-8.
Table 18-8. Amplifier 0 Gain Selection
AMP0G1
AMP0G0
Description
Gain 5
0
0
1
1
0
1
0
1
Gain 10
Gain 20
Gain 40
To ensure an accurate result, after the gain value has been changed, the amplifier input needs to have a quite stable input
value during at least 4 Amplifier synchronization clock periods.
• Bit 3 – AMPCMP0: Amplifier 0 - Comparator 0 Connection
Set this bit to connect the amplifier 0 to the comparator 0 positive input. In this configuration the comparator clock is twice the
amplifier clock. Clear this bit to normally use the Amplifier 0.
• Bit 2:0 – AMP0TS2,AMP0TS1,AMP0TS0: Amplifier 0 Clock Source Selection Bits
In accordance with Table 18-9 on page 219, these 3 bits select the event which will generate the clock for the amplifier 0.
This clock source is necessary to start the conversion on the amplified channel.
218
ATmega16/32/64/M1/C1 [DATASHEET]
7647O–AVR–01/15
MICROCHIP [ MICROCHIP ]
