ATMEGA8A-MU Atmel, ATMEGA8A-MU Datasheet - Page 99

• Manufacturer Part Number: ATMEGA8A-MU
• Description: MCU AVR 8K FLASH 16MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8A-MU

• 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: 23
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K 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: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Controller Family/series: AVR MEGA
• No. Of I/o's: 23
• Eeprom Memory Size: 512Byte
• Ram Memory Size: 1KB
• Cpu Speed: 16MHz
• No. Of Timers: 3
• Rohs Compliant: Yes
• Processor Series: ATMEGA8x
• Core: AVR8
• Data Bus Width: 8 bit
• Data Ram Size: 1 KB
• Interface Type: SPI, TWI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 23
• Number Of Timers: 3
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 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
• For Use With: ATSTK600 - DEV KIT FOR AVR/AVR32ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

16.11 Register Description
16.11.1
8159D–AVR–02/11
TCCR1A – Timer/Counter 1 Control Register A
Figure 16-13. Timer/Counter Timing Diagram, with Prescaler (f
• Bit 7:6 – COM1A1:0: Compare Output Mode for channel A
• Bit 5:4 – COM1B1:0: Compare Output Mode for channel 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 16-2.
Bit
Read/Write
Initial Value
COM1A1/
COM1B1
(PC and PFC PWM)
and ICFn
(CTC and FPWM)
(Update at TOP)
TOVn
0
0
1
1
TCNTn
TCNTn
OCRnx
(clk
as TOP)
clk
clk
I/O
(FPWM)
I/O
COM1A1
Tn
/8)
(if used
R/W
Compare Output Mode, Non-PWM
7
0
COM1A0/
COM1B0
0
1
0
1
COM1A0
R/W
6
0
TOP - 1
TOP - 1
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)
Old OCRnx Value
COM1B1
R/W
5
0
Table 16-2
COM1B0
R/W
4
0
shows the COM1x1:0 bit functionality when the
TOP
TOP
FOC1A
W
3
0
FOC1B
W
0
2
clk_I/O
BOTTOM
TOP - 1
New OCRnx Value
/8)
WGM11
R/W
1
0
ATmega8A
WGM10
BOTTOM + 1
R/W
0
0
TOP - 2
TCCR1A
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