ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 121

• Manufacturer Part Number: ATtiny43U
• Manufacturer: Atmel Corporation

Specifications of ATtiny43U

• Flash (kbytes): 4 Kbytes
• Pin Count: 20
• Max. Operating Frequency: 8 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 8
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 16
• Ext Interrupts: 16
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 4
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.25
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 0.7 to 5.5
• Operating Voltage (vcc): 0.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Pwm Channels: 4
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

16.6.1
16.6.2
16.7
8048B–AVR–03/09
ADC Noise Canceler
ADC Input Channels
ADC Voltage Reference
If both ADATE and ADEN is written to one, an interrupt event can occur at any time. If the
ADMUX Register is changed in this period, the user cannot tell if the next conversion is based
on the old or the new settings. ADMUX can be safely updated in the following ways:
When updating ADMUX in one of these conditions, the new settings will affect the next ADC
conversion.
When changing channel selections, the user should observe the following guidelines to ensure
that the correct channel is selected:
The ADC reference voltage (V
channels that exceed V
V
from the internal bandgap reference (V
The first ADC conversion result after switching reference voltage source may be inaccurate, and
the user is advised to discard this result.
The ADC features a noise canceler that enables conversion during sleep mode. This reduces
noise induced from the CPU core and other I/O peripherals. The noise canceler can be used
with ADC Noise Reduction and Idle mode. To make use of this feature, the following procedure
should be used:
CC
• When ADATE or ADEN is cleared.
• During conversion, minimum one ADC clock cycle after the trigger event.
• After a conversion, before the Interrupt Flag used as trigger source is cleared.
• In Single Conversion mode, always select the channel before starting the conversion. The
• In Free Running mode, always select the channel before starting the first conversion. The
• Make sure that the ADC is enabled and is not busy converting. Single Conversion mode must
• Enter ADC Noise Reduction mode (or Idle mode). The ADC will start a conversion once the
• If no other interrupts occur before the ADC conversion completes, the ADC interrupt will wake
channel selection may be changed one ADC clock cycle after writing one to ADSC. However,
the simplest method is to wait for the conversion to complete before changing the channel
selection.
channel selection may be changed one ADC clock cycle after writing one to ADSC. However,
the simplest method is to wait for the first conversion to complete, and then change the
channel selection. Since the next conversion has already started automatically, the next
result will reflect the previous channel selection. Subsequent conversions will reflect the new
channel selection.
be selected and the ADC conversion complete interrupt must be enabled.
CPU has been halted.
up the CPU and execute the ADC Conversion Complete interrupt routine. If another interrupt
wakes up the CPU before the ADC conversion is complete, that interrupt will be executed,
and an ADC Conversion Complete interrupt request will be generated when the ADC
, or internal 1.1V reference, or external AREF pin. The internal 1.1V reference is generated
REF
will result in codes close to 0x3FF. V
REF
) indicates the conversion range for the ADC. Single ended
BG
) through an internal amplifier.
REF
can be selected as either
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