ATtiny88 Automotive Atmel Corporation, ATtiny88 Automotive Datasheet - Page 106

• 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

12.10 Timer/Counter Timing Diagrams
106
ATtiny88 Automotive
The PWM frequency for the output when using phase and frequency correct PWM can be calcu-
lated by the following equation:
The N variable represents the prescaler divider (1, 8, 64, 256, or 1024).
The extreme values for the OCR1x Register represents special cases when generating a PWM
waveform output in the phase correct PWM mode. If the OCR1x is set equal to BOTTOM the
output will be continuously low and if set equal to TOP the output will be set to high for
non-inverted PWM mode. For inverted PWM the output will have the opposite logic values. If
OCR1A is used to define the TOP value and COM1A1:0 = 1, the OC1A output will toggle with a
50% duty cycle.
The Timer/Counter is a synchronous design and the timer clock (clk
clock enable signal in the following figures. The figures include information on when Interrupt
Flags are set, and when the OCR1x Register is updated with the OCR1x buffer value (only for
modes utilizing double buffering).
Figure 12-10. Timer/Counter Timing Diagram, Setting of OCF1x, no Prescaling
Figure 12-11
TCNTn
OCRnx
OCFnx
(clk
clk
clk
I/O
I/O
Tn
/1)
shows the same timing data, but with the prescaler enabled.
OCRnx - 1
f
OCnxPFCPWM
Figure 12-10
OCRnx
OCRnx Value
=
shows a timing diagram for the setting of OCF1x.
---------------------------------
2
f
clk_I/O
N
TOP
OCRnx + 1
T1
) is therefore shown as a
OCRnx + 2
9157B–AVR–01/10