ATtiny43U Atmel Corporation, ATtiny43U Datasheet - Page 26

• 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

6.2.3
6.2.4
26
ATtiny43U
Internal 128 kHz Oscillator
Default Clock Source
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table 6-5
Table 6-5.
Note:
The 128 kHz internal oscillator is a low power oscillator providing a clock of 128 kHz. The fre-
quency is nominal at 3V and 25°C. This clock may be select as the system clock by
programming the CKSEL Fuses to “11” as shown in
Table 6-6.
When this clock source is selected, start-up times are determined by the SUT Fuses as shown in
Table 6-7
Table 6-7.
Note:
The device is shipped with CKSEL = "0010", SUT = "10", and CKDIV8 programmed. The default
clock source is therefore the internal RC oscillator running at 8.0 MHz with the longest start-up
time and an initial system clock prescale setting of 8, resulting in a 1 MHz system clock. The
default setting ensures every user can make the desired clock source setting using any available
programming interface.
SUT1..0
SUT1..0
10
00
01
11
00
01
10
11
(2)
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
2.
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to 14CK + 4 ms to
below.
below.
14CK + 4 ms to ensure programming mode can be entered.
The device is shipped with this option selected.
ensure programming mode can be entered.
CKSEL3..0
Start-up times for Internal Calibrated RC Oscillator Clock Selection
128 kHz Internal Oscillator Operating Modes
Start-up Times for the 128 kHz Internal Oscillator
0011
from Power-down
from Power-down
Start-up Time
Start-up Time
6 CK
6 CK
6 CK
6 CK
6 CK
6 CK
Additional Delay from
Reset (V
Additional Delay
Reserved
Reserved
14CK + 64 ms
14CK + 64 ms
14CK + 4 ms
14CK + 4 ms
from Reset
Table 6-6
14CK
14CK
CC
Nominal Frequency
(1)
(1)
= 5.0V)
below.
128 kHz
Recommended Usage
BOD enabled
Fast rising power
Slowly rising power
BOD enabled
Fast rising power
Slowly rising power
Recommended Usage
8048B–AVR–03/09