ATMEGA165-16AI Atmel, ATMEGA165-16AI Datasheet - Page 138

• Manufacturer Part Number: ATMEGA165-16AI
• Description: IC AVR MCU 16K 16MHZ 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA165-16AI

• 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: 16KB (8K 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: 64-TQFP, 64-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Timer/Counter Prescaler
General Timer/Counter
Control Register – GTCCR
2573G–AVR–07/09
Figure 64. Prescaler for Timer/Counter2
The clock source for Timer/Counter2 is named clk
the main system I/O clock clk
chronously clocked from the TOSC1 pin. This enables use of Timer/Counter2 as a Real
Time Counter (RTC). When AS2 is set, pins TOSC1 and TOSC2 are disconnected from
Port C. A crystal can then be connected between the TOSC1 and TOSC2 pins to serve
as an independent clock source for Timer/Counter2. The Oscillator is optimized for use
with a 32.768 kHz crystal. If applying an external clock on TOSC1, the EXCLK bit in
ASSR must be set.
For Timer/Counter2, the possible prescaled selections are: clk
clk
selected. Setting the PSR2 bit in GTCCR resets the prescaler. This allows the user to
operate with a predictable prescaler.
• Bit 1 – PSR2: Prescaler Reset Timer/Counter2
When this bit is one, the Timer/Counter2 prescaler will be reset. This bit is normally
cleared immediately by hardware. If the bit is written when Timer/Counter2 is operating
in asynchronous mode, the bit will remain one until the prescaler has been reset. The bit
will not be cleared by hardware if the TSM bit is set. Refer to the description of the “Bit 7
– TSM: Timer/Counter Synchronization Mode” on page 90 for a description of the
Timer/Counter Synchronization mode.
Bit
Read/Write
Initial Value
TOSC1
T2S
clk
PSR2
CS20
CS21
CS22
AS2
I/O
/128, clk
TSM
R/W
T2S
7
0
/256, and clk
R
6
–
0
clk
T2S
IO
. By setting the AS2 bit in ASSR, Timer/Counter2 is asyn-
T2S
R
5
–
0
Clear
/1024. Additionally, clk
TIMER/COUNTER2 CLOCK SOURCE
4
–
R
0
0
10-BIT T/C PRESCALER
R
3
–
0
T2S
clk
. clk
T2
T2S
T2S
R
2
–
0
as well as 0 (stop) may be
ATmega165/V
is by default connected to
T2S
PSR2
/8, clk
R/W
1
0
T2S
PSR10
R/W
/32, clk
0
0
GTCCR
T2S
/64,
138