ATTINY88-15MZ Atmel, ATTINY88-15MZ Datasheet - Page 79

• Manufacturer Part Number: ATTINY88-15MZ
• Description: IC MCU AVR 8B 8KB FLASH 32QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY88-15MZ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 28
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

11.5.1
11.5.2
11.6
11.6.1
9157B–AVR–01/10
Modes of Operation
Compare Match Blocking by TCNT0 Write
Using the Output Compare Unit
Normal Mode
Figure 11-3. Output Compare Unit, Block Diagram
All CPU write operations to the TCNT0 Register will block any compare match that occur in the
next timer clock cycle, even when the timer is stopped. This feature allows OCR0x to be initial-
ized to the same value as TCNT0 without triggering an interrupt when the Timer/Counter clock is
enabled.
Since writing TCNT0 in any mode of operation will block all compare matches for one timer clock
cycle, there are risks involved when changing TCNT0 when using the Output Compare Unit,
independently of whether the Timer/Counter is running or not. If the value written to TCNT0
equals the OCR0x value, the compare match will be missed, resulting in incorrect waveform
generation.
The mode of operation, i.e., the behavior of the Timer/Counter and the Output Compare pins, is
defined by the CTC0 bit.
For detailed timing information refer to
The simplest mode of operation is the Normal mode (CTC0 = 0). In this mode the counting direc-
tion is always up (incrementing), and no counter clear is performed. The counter simply overruns
when it passes its maximum 8-bit value (TOP = 0xFF) and then restarts from the bottom (0x00).
In normal operation the Timer/Counter Overflow Flag (TOV0) will be set in the same timer clock
cycle as the TCNT0 becomes zero. The TOV0 Flag in this case behaves like a ninth bit, except
that it is only set, not cleared. However, combined with the timer overflow interrupt that automat-
ically clears the TOV0 Flag, the timer resolution can be increased by software. There are no
special cases to consider in the Normal mode, a new counter value can be written anytime.
The Output Compare unit can be used to generate interrupts at some given time.
OCRnx
“Timer/Counter Timing Diagrams” on page
=
OCFnx (Int.Req.)
(8-bit Comparator )
DATA BUS
ATtiny88 Automotive
TCNTn
80.
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