ATTINY24-15SSZ Atmel, ATTINY24-15SSZ Datasheet - Page 77

• Manufacturer Part Number: ATTINY24-15SSZ
• Description: MCU AVR 2K FLASH 15MHZ 14-SOIC
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY24-15SSZ

• Package / Case: 14-SOIC (3.9mm Width), 14-SOL
• 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: 128 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Program Memory Size: 2KB (2K x 8)
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Cpu Family: ATtiny
• Device Core: AVR
• Device Core Size: 8b
• Frequency (max): 16MHz
• Interface Type: SPI/UART
• Total Internal Ram Size: 128Byte
• # I/os (max): 12
• Number Of Timers - General Purpose: 2
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• On-chip Adc: 8-chx10-bit
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 125C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 14
• Package Type: SOIC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

13.7.3
7701D–AVR–09/10
Fast PWM Mode
The timing diagram for the CTC mode is shown in
(TCNT0) increases until a Compare Match occurs between TCNT0 and OCR0A, and then
counter (TCNT0) is cleared.
Figure 13-5. CTC Mode, Timing Diagram
An interrupt can be generated each time the counter value reaches the top value by using the
OCF0A flag. If the interrupt is enabled, the interrupt handler routine can be used for updating
the top value. However, changing top to a value close to bottom when the counter is running
with no or a low prescaler value must be done with care since the CTC mode does not have
the double buffering feature. If the new value written to OCR0A is lower than the current value
of TCNT0, the counter will miss the compare match. The counter will then have to count to its
maximum value (0xFF) and wrap around starting at 0x00 before the compare match can
occur.
For generating a waveform output in CTC mode, the OC0A output can be set to toggle its log-
ical level on each compare match by setting the compare output mode bits to toggle mode
(COM0A1:0 = 1). The OC0A value will not be visible on the port pin unless the data direction
for the pin is set to output. The waveform generated will have a maximum frequency of
0
lowing equation:
The variable N represents the prescale factor (1, 8, 64, 256, or 1024).
As for the normal mode of operation, the TOV0 flag is set on the same timer clock cycle on
which the counter counts from max to 0x00.
The fast pulse width modulation, or fast PWM, mode (WGM02:0 = 3 or 7) provides a high-fre-
quency PWM waveform generation option. The fast PWM mode differs from the other PWM
option by its single-slope operation. The counter counts from bottom to top then restarts from
bottom. Top is defined as 0xFF when WGM2:0 = 3, and as OCR0A when WGM2:0 = 7. In
non-inverting compare output mode, the output compare (OC0x) is cleared on the compare
match between TCNT0 and OCR0x, and set at bottom. In inverting compare output mode, the
output is set on compare match and cleared at bottom. Due to the single-slope operation, the
operating frequency of the fast PWM mode can be twice as high as the phase correct PWM
mode that uses dual-slope operation.
f
OCnx
= f
clk_I/O
TCNTn
OCn
(Toggle)
Period
=
/2 when OCR0A is set to zero (0x00). The waveform frequency is defined by the fol-
------------------------------------------------------ -
2
N
f
clk_I/O
1
+
1
OCRnx
Atmel ATtiny24/44/84 [Preliminary]
2
3
Figure 13-5 on page
4
77. The counter value
OCnx Interrupt Flag Set
(COMnx1:0 = 1)
77