AT90PWM3-16SQ Atmel, AT90PWM3-16SQ Datasheet - Page 114

• Manufacturer Part Number: AT90PWM3-16SQ
• Description: IC AVR MCU FLASH 8K 32SOIC
• Manufacturer: Atmel
• Series: AVR® 90PWM Lightingr

Specifications of AT90PWM3-16SQ

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 27
• Program Memory Size: 8KB (8K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 11x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 32-SOIC (7.5mm Width)
• Processor Series: AT90PWMx
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 27
• Number Of Timers: 2
• Operating Supply Voltage: 2.7 V to 5.5 V
• Maximum Operating Temperature: + 105 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT, ATAVRFBKIT, ATAVRISP2
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 11 Channel
• On-chip Dac: 10 bit, 1 Channel
• For Use With: ATSTK600-SOIC - STK600 SOCKET/ADAPTER FOR SOICATAVRMC200 - KIT EVAL FOR AT90PWM3 ASYNCATAVRFBKIT - KIT DEMO BALLAST FOR AT90PWM2ATSTK520 - ADAPTER KIT FOR 90PWM
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.8.1
15.8.2
114
AT90PWM2/3/2B/3B
Normal Mode
Clear Timer on Compare Match (CTC) Mode
while the Waveform Generation mode bits do. The COMnx1:0 bits control whether the PWM out-
put generated should be inverted or not (inverted or non-inverted PWM). For non-PWM modes
the COMnx1:0 bits control whether the output should be set, cleared or toggle at a compare
match
For detailed timing information refer to
The simplest mode of operation is the Normal mode (WGMn3:0 = 0). In this mode the counting
direction is always up (incrementing), and no counter clear is performed. The counter simply
overruns when it passes its maximum 16-bit value (MAX = 0xFFFF) and then restarts from the
BOTTOM (0x0000). In normal operation the Timer/Counter Overflow Flag (TOVn) will be set in
the same timer clock cycle as the TCNTn becomes zero. The TOVn Flag in this case behaves
like a 17th bit, except that it is only set, not cleared. However, combined with the timer overflow
interrupt that automatically clears the TOVn Flag, the timer resolution can be increased by soft-
ware. There are no special cases to consider in the Normal mode, a new counter value can be
written anytime.
The Input Capture unit is easy to use in Normal mode. However, observe that the maximum
interval between the external events must not exceed the resolution of the counter. If the interval
between events are too long, the timer overflow interrupt or the prescaler must be used to
extend the resolution for the capture unit.
The Output Compare units can be used to generate interrupts at some given time. Using the
Output Compare to generate waveforms in Normal mode is not recommended, since this will
occupy too much of the CPU time.
In Clear Timer on Compare or CTC mode (WGMn3:0 = 4 or 12), the OCRnA or ICRn Register
are used to manipulate the counter resolution. In CTC mode the counter is cleared to zero when
the counter value (TCNTn) matches either the OCRnA (WGMn3:0 = 4) or the ICRn (WGMn3:0 =
12). The OCRnA or ICRn define the top value for the counter, hence also its resolution. This
mode allows greater control of the compare match output frequency. It also simplifies the opera-
tion of counting external events.
The timing diagram for the CTC mode is shown in
increases until a compare match occurs with either OCRnA or ICRn, and then counter (TCNTn)
is cleared.
Figure 15-6. CTC Mode, Timing Diagram
TCNTn
OCnA
(Toggle)
Period
(See “Compare Match Output Unit” on page
1
2
“Timer/Counter Timing Diagrams” on page
3
112.)
Figure
4
15-6. The counter value (TCNTn)
OCnA Interrupt Flag Set
or ICFn Interrupt Flag Set
(Interrupt on TOP)
(COMnA1:0 = 1)
121.
4317J–AVR–08/10