ATmega88 Automotive Atmel Corporation, ATmega88 Automotive Datasheet - Page 153

• Manufacturer Part Number: ATmega88 Automotive
• Manufacturer: Atmel Corporation

Specifications of ATmega88 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: 23
• Ext Interrupts: 24
• Usb Speed: No
• Usb Interface: No
• Spi: 2
• Twi (i2c): 1
• Uart: 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: No
• Crypto Engine: No
• Sram (kbytes): 1
• Eeprom (bytes): 512
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 150
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 3
• Output Compare Channels: 6
• Input Capture Channels: 1
• Pwm Channels: 6
• 32khz Rtc: Yes
• Calibrated Rc Oscillator: Yes

7530I–AVR–02/10
During asynchronous operation, the synchronization of the Interrupt Flags for the asynchronous
timer takes 3 processor cycles plus one timer cycle. The timer is therefore advanced by at least
one before the processor can read the timer value causing the setting of the Interrupt Flag. The
Output Compare pin is changed on the timer clock and is not synchronized to the processor
clock.
• When the asynchronous operation is selected, the 32.768 kHz Oscillator for Timer/Counter2
• Description of wake up from Power-save or ADC Noise Reduction mode when the timer is
• Reading of the TCNT2 Register shortly after wake-up from Power-save may give an incorrect
is always running, except in Power-down and Standby modes. After a Power-up Reset or
wake-up from Power-down or Standby mode, the user should be aware of the fact that this
Oscillator might take as long as one second to stabilize. The user is advised to wait for at
least one second before using Timer/Counter2 after power-up or wake-up from Power-down
or Standby mode. The contents of all Timer/Counter2 Registers must be considered lost after
a wake-up from Power-down or Standby mode due to unstable clock signal upon start-up, no
matter whether the Oscillator is in use or a clock signal is applied to the TOSC1 pin.
clocked asynchronously: When the interrupt condition is met, the wake up process is started
on the following cycle of the timer clock, that is, the timer is always advanced by at least one
before the processor can read the counter value. After wake-up, the MCU is halted for four
cycles, it executes the interrupt routine, and resumes execution from the instruction following
SLEEP.
result. Since TCNT2 is clocked on the asynchronous TOSC clock, reading TCNT2 must be
done through a register synchronized to the internal I/O clock domain. Synchronization takes
place for every rising TOSC1 edge. When waking up from Power-save mode, and the I/O
clock (clk
sleep) until the next rising TOSC1 edge. The phase of the TOSC clock after waking up from
Power-save mode is essentially unpredictable, as it depends on the wake-up time. The
recommended procedure for reading TCNT2 is thus as follows:
a. Write any value to either of the registers OCR2x or TCCR2x.
b. Wait for the corresponding Update Busy Flag to be cleared.
c. Read TCNT2.
I/O
) again becomes active, TCNT2 will read as the previous value (before entering
ATmega48/88/168 Automotive
153