ATMEGA324A-PU Atmel, ATMEGA324A-PU Datasheet - Page 133

• Manufacturer Part Number: ATMEGA324A-PU
• Description: IC MCU AVR 32K 20MHZ 40PDIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA324A-PU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 20MHz
• 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): 1.8 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)
• Controller Family/series: Atmega
• No. Of I/o's: 32
• Eeprom Memory Size: 1KB
• Ram Memory Size: 2KB
• Cpu Speed: 20MHz
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15.11 Register Description
15.11.1
8272A–AVR–01/10
TCCR1A – Timer/Counter1 Control Register A
Figure 15-13. Timer/Counter Timing Diagram, with Prescaler (f
• Bit 7:6 – COMnA1:0: Compare Output Mode for Channel A
• Bit 5:4 – COMnB1:0: Compare Output Mode for Channel B
The COMnA1:0 and COMnB1:0 control the Output Compare pins (OCnA and OCnB respec-
tively) behavior. If one or both of the COMnA1:0 bits are written to one, the OCnA output
overrides the normal port functionality of the I/O pin it is connected to. If one or both of the
COMnB1:0 bit are written to one, the OCnB 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 OCnA or OCnB pin must be set in order to enable the output driver.
When the OCnA or OCnB is connected to the pin, the function of the COMnx1:0 bits is depen-
dent of the WGMn3:0 bits setting.
when the WGMn3:0 bits are set to a Normal or a CTC mode (non-PWM).
Table 15-2.
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Bit
(0x80)
Read/Write
Initial Value
COMnA1/COMnB1
and ICF n
(PC and PFC PWM)
TOVn
(CTC and FPWM)
(Update at TOP)
0
0
1
1
TCNTn
TCNTn
OCRnx
(clk
as TOP)
clk
clk
I/O
(FPWM)
I/O
Tn
/8)
(if used
COM1A1
Compare Output Mode, non-PWM
R/W
7
0
COM1A0
COMnA0/COMnB0
R/W
6
0
TOP - 1
TOP - 1
Old OCRnx Value
0
1
0
1
COM1B1
Table 15-2 on page 133
R/W
5
0
COM1B0
R/W
4
0
Description
Normal port operation, OCnA/OCnB disconnected.
Toggle OCnA/OCnB on Compare Match.
Clear OCnA/OCnB on Compare Match (Set output to
low level).
Set OCnA/OCnB on Compare Match (Set output to
high level).
TOP
TOP
R
3
–
0
shows the COMnx1:0 bit functionality
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