ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 24

• 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

6.1.4
6.2
6.2.1
24
Clock Sources
ATtiny43U
ADC Clock – clk
External Clock
The ADC is provided with a dedicated clock domain. This allows halting the CPU and I/O clocks
in order to reduce noise generated by digital circuitry. This gives more accurate ADC conversion
results.
The device has the following clock source options, selectable by Flash Fuse bits as shown
below. The clock from the selected source is input to the AVR clock generator, and routed to the
appropriate modules.
Table 6-1.
Note:
To drive the device from an external clock source, CLKI should be driven as shown in
on page
“0000” (see
Table 6-2.
Figure 6-2.
ADC
Device Clocking Option
External Clock (see
Calibrated Internal 8 MHz Oscillator (see
Internal 128 kHz Oscillator (see
Reserved
1. For all fuses “1” means unprogrammed while “0” means programmed.
24. To run the device on an external clock, the CKSEL Fuses must be programmed to
Table
CKSEL3..0
Device Clocking Options Select
Crystal Oscillator Clock Frequency
External Clock Drive Configuration
0000
EXTERNAL
6-2).
page
SIGNAL
CLOCK
24)
page
26)
page
25)
(1)
CLKI
GND
Frequency
0 - 8 MHz
0001, 0100-1111
CKSEL3..0
0000
0010
0011
8048B–AVR–03/09
Figure 6-2