ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 133

• Manufacturer Part Number: ATMEGA649A-AU
• Description: IC MCU AVR 64K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA649A-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.11 Register Description
15.11.1
8284A–AVR–10/10
TCCR1A – Timer/Counter1 Control Register A
Figure 15-13. Timer/Counter Timing Diagram, with Prescaler (f
• Bit 7:6 – COM1A1:0: Compare Output Mode for Unit A
• Bit 5:4 – COM1B1:0: Compare Output Mode for Unit B
The COM1A1:0 and COM1B1:0 control the Output Compare pins (OC1A and OC1B respec-
tively) behavior. If one or both of the COM1A1:0 bits are written to one, the OC1A output
overrides the normal port functionality of the I/O pin it is connected to. If one or both of the
COM1B1:0 bit are written to one, the OC1B output overrides the normal port functionality of the
I/O pin it is connected to. However, note that the Data Direction Register (DDR) bit correspond-
ing to the OC1A or OC1B pin must be set in order to enable the output driver.
When the OC1A or OC1B is connected to the pin, the function of the COM1x1:0 bits is depen-
dent of the WGM13:0 bits setting.
WGM13:0 bits are set to a Normal or a CTC mode (non-PWM).
Table 15-2.
Bit
(0x80)
Read/Write
Initial Value
COM1A1/COM1B1
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
and ICF n
(PC and PFC PWM)
TOVn
(CTC and FPWM)
(Update at TOP)
0
0
1
1
OCRnx
TCNTn
TCNTn
as TOP)
(clk
clk
clk
I/O
(FPWM)
I/O
Tn
/8)
COM1A1
(if used
Compare Output Mode, non-PWM
R/W
7
0
COM1A0
COM1A0/COM1B0
R/W
6
0
TOP - 1
TOP - 1
Old OCRnx Value
0
1
0
1
COM1B1
R/W
Table 15-2
5
0
COM1B0
R/W
4
0
Description
Normal port operation, OC1A/OC1B disconnected.
Toggle OC1A/OC1B on Compare Match.
Clear OC1A/OC1B on Compare Match (Set output to
low level).
Set OC1A/OC1B on Compare Match (Set output to
high level).
shows the COM1x1:0 bit functionality when the
TOP
TOP
R
3
–
0
BOTTOM
TOP - 1
clk_I/O
R
2
–
0
New OCRnx Value
/8)
WGM11
R/W
1
0
BOTTOM + 1
TOP - 2
WGM10
R/W
0
0
TCCR1A
133