ATtiny88 Automotive Atmel Corporation, ATtiny88 Automotive Datasheet - Page 117

• Manufacturer Part Number: ATtiny88 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATtiny88 Automotive

• Flash (kbytes): 8 Kbytes
• Pin Count: 32
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 12
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 28
• Ext Interrupts: 28
• Usb Speed: No
• Usb Interface: No
• Spi: 1
• Twi (i2c): 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 8
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 0.5
• Eeprom (bytes): 64
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: Yes
• Temp. Range (deg C): -40 to 125
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 2
• Output Compare Channels: 4
• Input Capture Channels: 1
• Pwm Channels: 2
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

ATtiny88 Automotive
The synchronization and edge detector logic introduces a delay of 2.5 to 3.5 system clock cycles
from an edge has been applied to the T1/T0 pin to the counter is updated.
Enabling and disabling of the clock input must be done when T1/T0 has been stable for at least
one system clock cycle, otherwise it is a risk that a false Timer/Counter clock pulse is generated.
Each half period of the external clock applied must be longer than one system clock cycle to
ensure correct sampling. The external clock must be guaranteed to have less than half the sys-
tem clock frequency (f
< f
/2) given a 50% duty cycle. Since the edge detector uses
ExtClk
clk_I/O
sampling, the maximum frequency of an external clock it can detect is half the sampling fre-
quency (Nyquist sampling theorem). However, due to variation of the system clock frequency
and duty cycle caused by oscillator source tolerances, it is recommended that maximum fre-
quency of an external clock source is less than f
/2.5.
clk_I/O
An external clock source can not be prescaled.
(1)
Figure 13-2. Prescaler for Timer/Counter0 and Timer/Counter1
clk
I/O
Clear
PSRSYNC
T0
Synchronization
T1
Synchronization
clk
clk
T1
T0
T1/T0)
Note:
1. The synchronization logic on the input pins (
is shown in
Figure
13-1.
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