ATMEGA32-16PU Atmel, ATMEGA32-16PU Datasheet - Page 115

• Manufacturer Part Number: ATMEGA32-16PU
• Description: IC AVR MCU 32K 16MHZ 5V 40DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32-16PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Processor Series: ATMEGA32x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 2 KB
• Interface Type: 2-Wire/SPI/USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 32
• Number Of Timers: 3
• Operating Supply Voltage: 4.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 8-ch x 10-bit
• A/d Inputs: 8-Channel, 10-Bit
• Cpu Speed: 16 MIPS
• Eeprom Memory: 1K Bytes
• Input Output: 32
• Interface: 2-Wire/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Timers: 2-8-bit, 1-16-bit
• Voltage, Range: 4.5-5.5 V
• Data Rom Size: 1024 B
• Height: 4.83 mm
• Length: 52.58 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4.5 V
• Width: 13.97 mm
• Controller Family/series: AVR MEGA
• No. Of I/o's: 32
• Eeprom Memory Size: 1024Byte
• Ram Memory Size: 2KB
• Rohs Compliant: Yes
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600-TQFP32 - STK600 SOCKET/ADAPTER 32-TQFPATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK600-DIP40 - STK600 SOCKET/ADAPTER 40-PDIP770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAGATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATAVRISP2 - PROGRAMMER AVR IN SYSTEMATJTAGICE2 - AVR ON-CHIP D-BUG SYSTEMATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Force Output Compare
Compare Match Blocking by
TCNT2 Write
Using the Output Compare
Unit
Compare Match Output
Unit
2503G–AVR–11/04
The OCR2 Register is double buffered when using any of the Pulse Width Modulation
(PWM) modes. For the normal and Clear Timer on Compare (CTC) modes of operation,
the double buffering is disabled. The double buffering synchronizes the update of the
OCR2 Compare Register to either top or bottom of the counting sequence. The synchro-
nization prevents the occurrence of odd-length, non-symmetrical PWM pulses, thereby
making the output glitch-free.
The OCR2 Register access may seem complex, but this is not case. When the double
buffering is enabled, the CPU has access to the OCR2 Buffer Register, and if double
buffering is disabled the CPU will access the OCR2 directly.
In non-PWM waveform generation modes, the match output of the comparator can be
forced by writing a one to the Force Output Compare (FOC2) bit. Forcing compare
match will not set the OCF2 Flag or reload/clear the timer, but the OC2 pin will be
updated as if a real compare match had occurred (the COM21:0 bits settings define
whether the OC2 pin is set, cleared or toggled).
All CPU write operations to the TCNT2 Register will block any compare match that
occurs in the next timer clock cycle, even when the timer is stopped. This feature allows
OCR2 to be initialized to the same value as TCNT2 without triggering an interrupt when
the Timer/Counter clock is enabled.
Since writing TCNT2 in any mode of operation will block all compare matches for one
timer clock cycle, there are risks involved when changing TCNT2 when using the output
compare unit, independently of whether the Timer/Counter is running or not. If the value
written to TCNT2 equals the OCR2 value, the compare match will be missed, resulting
in incorrect waveform generation. Similarly, do not write the TCNT2 value equal to BOT-
TOM when the counter is downcounting.
The setup of the OC2 should be performed before setting the Data Direction Register for
the port pin to output. The easiest way of setting the OC2 value is to use the Force Out-
put Compare (FOC2) strobe bit in Normal mode. The OC2 Register keeps its value even
when changing between Waveform Generation modes.
Be aware that the COM21:0 bits are not double buffered together with the compare
value. Changing the COM21:0 bits will take effect immediately.
The Compare Output mode (COM21:0) bits have two functions. The Waveform Genera-
tor uses the COM21:0 bits for defining the Output Compare (OC2) state at the next
compare match. Also, the COM21:0 bits control the OC2 pin output source. Figure 56
shows a simplified schematic of the logic affected by the COM21:0 bit setting. The I/O
Registers, 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 COM21:0
bits are shown. When referring to the OC2 state, the reference is for the internal OC2
Register, not the OC2 pin.
ATmega32(L)
115