ATTINY44-15MZ Atmel, ATTINY44-15MZ Datasheet - Page 76

• Manufacturer Part Number: ATTINY44-15MZ
• Description: MCU AVR 4K FLASH 15MHZ 20-QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY44-15MZ

• Package / Case: 20-QFN Exposed Pad
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 12
• Eeprom Size: 256 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Program Memory Size: 4KB (4K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Processor Series: ATTINY4x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 256 B
• Interface Type: SPI, UART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 12
• Number Of Timers: 2
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 8 Channel
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

13.5.3
13.6
76
Compare Match Output Unit
Atmel ATtiny24/44/84 [Preliminary]
Using the Output Compare Unit
Since writing TCNT0 in any mode of operation will block all compare matches for one timer
clock cycle, there are risks involved in 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. Similarly, do not write the TCNT0 value equal to bottom when the counter is
down-counting.
The setup of the OC0x should be performed before setting the data direction register for the
port pin to output. The easiest way of setting the OC0x value is to use the force output com-
pare (0x) strobe bits in normal mode. The OC0x registers keep their values even when
changing between waveform generation modes.
Be aware that the COM0x1:0 bits are not double buffered together with the compare value.
Changes to the COM0x1:0 bits will take effect immediately.
The Compare Output mode (COM0x1:0) bits have two functions. The Waveform Generator
uses the COM0x1:0 bits for defining the Output Compare (OC0x) state at the next Compare
Match. Also, the COM0x1:0 bits control the OC0x pin output source.
shows a simplified schematic of the logic affected by the COM0x1:0 bit setting. The I/O regis-
ters, I/O bits, and I/O pins in the figure are shown in bold. Only the parts of the general I/O port
control registers (DDR and PORT) that are affected by the COM0x1:0 bits are shown. When
referring to the OC0x state, the reference is for the internal OC0x register, not the OC0x pin. If
a system reset occurs, the OC0x register is reset to "0".
Figure 13-4. Compare Match Output Unit, Schematic
The general I/O port function is overridden by the output compare (OC0x) from the waveform
generator if either of the COM0x1:0 bits are set. However, the OC0x pin direction (input or out-
put) is still controlled by the data direction register (DDR) for the port pin. The data direction
register bit for the OC0x pin (DDR_OC0x) must be set as output before the OC0x value is vis-
ible on the pin. The port override function is independent of the waveform generation mode.
COMnx1
COMnx0
FOCn
clk
I/O
Waveform
Generator
D
D
D
PORT
OCnx
DDR
Q
Q
Q
1
0
Figure 13-4 on page 76
OCn
Pin
7701E–AVR–02/11