ATMEGA645P-MUR Atmel, ATMEGA645P-MUR Datasheet - Page 130

• Manufacturer Part Number: ATMEGA645P-MUR
• Description: MCU AVR 64KB FLASH 16MHZ 64QFN
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA645P-MUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, 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-VFQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.11 Register Description
15.11.1
130
ATmega165A/165PA/325A/325PA/3250A/3250PA/645A/645P/645
TCCR1A – Timer/Counter1 Control Register A
• Bit 7:6 – COM1A[1:0]: Compare Output Mode for Unit A
• Bit 5:4 – COM1B[1:0]: Compare Output Mode for Unit B
The COM1A[1:0] and COM1B[1:0] control the Output Compare pins (OC1A and OC1B respec-
tively) behavior. If one or both of the COM1A[1:0] 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
COM1B[1:0] 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 COM1x[1:0] bits is depen-
dent of the WGM1[3:0] bits setting...
WGM1[3:0] bits are set to a Normal or a CTC mode (non-PWM).
Table 15-2.
Table 15-3
PWM mode.
Table 15-3.
Note:
Bit
(0x80)
Read/Write
Initial Value
COM1A1/COM1B1
COM1A1/COM1B1
1. A special case occurs when OCR1A/OCR1B equals TOP and COM1A1/COM1B1 is set. In
0
0
1
1
0
0
1
1
this case the compare match is ignored, but the set or clear is done at TOP.
Mode” on page 122.
shows the COM1x[1:0] bit functionality when the WGM1[3:0] bits are set to the fast
COM1A1
Compare Output Mode, non-PWM
Compare Output Mode, Fast PWM
R/W
7
0
COM1A0
COM1A0/COM1B0
COM1A0/COM1B0
R/W
6
0
for more details.
0
1
0
1
0
1
0
1
COM1B1
R/W
5
0
Table 15-2
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).
Description
Normal port operation, OC1A/OC1B disconnected.
WGM1[3:0] = 14 or 15: Toggle OC1A on Compare
Match, OC1B disconnected (normal port operation).
For all other WGM1 settings, normal port operation,
OC1A/OC1B disconnected.
Clear OC1A/OC1B on Compare Match, set
OC1A/OC1B at BOTTOM (non-inverting mode)
Set OC1A/OC1B on Compare Match, clear
OC1A/OC1B at BOTTOM (inverting mode)
shows the COM1x[1:0] bit functionality when the
(1)
R
3
–
0
R
2
–
0
WGM11
R/W
1
0
WGM10
See ”Fast PWM
R/W
0
0
8285B–AVR–03/11
TCCR1A