ATMEGA32A-PU Atmel, ATMEGA32A-PU Datasheet - Page 77

• Manufacturer Part Number: ATMEGA32A-PU
• Description: MCU AVR 32K FLASH 16MHZ 40-PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA32A-PU

• 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): 2.7 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
• 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: 10 bit, 8 Channel
• Package: 40PDIP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Rom Size: 1024 B
• Height: 4.83 mm
• Length: 52.58 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 2.7 V
• Width: 13.97 mm
• Controller Family/series: AVR MEGA
• No. Of I/o's: 32
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 16MHz
• Rohs Compliant: Yes
• For Use With: ATSTK524 - KIT STARTER ATMEGA32M1/MEGA32C1ATSTK600 - DEV KIT FOR AVR/AVR32ATAVRDRAGON - KIT DRAGON 32KB FLASH MEM AVRATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14.6
8155C–AVR–02/11
Compare Match Output Unit
the OCR0 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 downcounting.
The setup of the OC0 should be performed before setting the Data Direction Register for the port
pin to output. The easiest way of setting the OC0 value is to use the Force Output Compare
(FOC0) strobe bits in Normal mode. The OC0 Register keeps its value even when changing
between waveform generation modes.
Be aware that the COM0[1:0] bits are not double buffered together with the compare value.
Changing the COM0[1:0] bits will take effect immediately.
The Compare Output mode (COM0[1:0]) bits have two functions. The Waveform Generator uses
the COM0[1:0] bits for defining the Output Compare (OC0) state at the next compare match.
Also, the COM0[1:0] bits control the OC0 pin output source.
schematic of the logic affected by the COM0[1:0] 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 COM0[1:0] bits are shown. When referring to the OC0
state, the reference is for the internal OC0 Register, not the OC0 pin. If a System Reset occur,
the OC0 Register is reset to “0”.
Figure 14-4. Compare Match Output Unit, Schematic
The general I/O port function is overridden by the Output Compare (OC0) from the Waveform
Generator if either of the COM0[1:0] bits are set. However, the OC0 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 OC0 pin (DDR_OC0) must be set as output before the OC0 value is visible
on the pin. The port override function is independent of the Waveform Generation mode.
The design of the output compare pin logic allows initialization of the OC0 state before the out-
put is enabled. Note that some COM01:0 bit settings are reserved for certain modes of
operation.
See “Register Description” on page 84.
COMn1
COMn0
FOCn
clk
I/O
Waveform
Generator
D
D
D
PORT
DDR
OCn
Q
Q
Q
1
0
Figure 14-4
ATmega32A
shows a simplified
OCn
Pin
77