ATmega88 Automotive Atmel Corporation, ATmega88 Automotive Datasheet - Page 31

• 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

6.6.1
7530I–AVR–02/10
Oscillator Calibration Register – OSCCAL
When this Oscillator is selected, start-up times are determined by the SUT Fuses as shown in
Table 6-9 on page
Table 6-9.
Note:
• Bits 7..0 – CAL7..0: Oscillator Calibration Value
The Oscillator Calibration Register is used to trim the Calibrated Internal RC Oscillator to
remove process variations from the oscillator frequency. The factory-calibrated value is automat-
ically written to this register during chip reset, giving an oscillator frequency of 8.0 MHz at 25°C.
The application software can write this register to change the oscillator frequency. The oscillator
can be calibrated to any frequency in the range 7.3 - 8.1 MHz within ±1% accuracy. Calibration
outside that range is not guaranteed.
Note that this oscillator is used to time EEPROM and Flash write accesses, and these write
times will be affected accordingly. If the EEPROM or Flash are written, do not calibrate to more
than 8.8 MHz. Otherwise, the EEPROM or Flash write may fail.
The CAL7 bit determines the range of operation for the oscillator. Setting this bit to 0 gives the
lowest frequency range, setting this bit to 1 gives the highest frequency range. The two fre-
quency ranges are overlapping, in other words a setting of OSCCAL = 0x7F gives a higher
frequency than OSCCAL = 0x80.
The CAL6..0 bits are used to tune the frequency within the selected range. A setting of 0x00
gives the lowest frequency in that range, and a setting of 0x7F gives the highest frequency in the
range. Incrementing CAL6..0 by 1 will give a frequency increment of less than 2% in the fre-
quency range 7.3 - 8.1 MHz.
Bit
Read/Write
Initial Value
Power Conditions
BOD enabled
Fast rising power
Slowly rising power
1. If the RSTDISBL fuse is programmed, this start-up time will be increased to
2.
14CK + 4.1 ms to ensure programming mode can be entered.
The device is shipped with this option selected.
Start-up times for the internal calibrated RC Oscillator clock selection
CAL7
R/W
7
31.
CAL6
R/W
6
Power-down and Power-save
Start-up Time from
CAL5
R/W
5
Device Specific Calibration Value
Reserved
ATmega48/88/168 Automotive
6 CK
6 CK
6 CK
CAL4
R/W
4
CAL3
R/W
3
CAL2
Additional Delay from
R/W
2
Reset (V
14CK + 65 ms
14CK + 4.1 ms
14CK
CAL1
R/W
CC
1
(1)
= 5.0V)
(2)
CAL0
R/W
0
SUT1..0
OSCCAL
00
01
10
11
31