ATMEGA103L-4AI Atmel, ATMEGA103L-4AI Datasheet - Page 38

• Manufacturer Part Number: ATMEGA103L-4AI
• Description: IC MCU 128K 4MHZ A/D LV 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA103L-4AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 4MHz
• Connectivity: SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• For Use With: ATSTK501 - ADAPTER KIT FOR 64PIN AVR MCU
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Timer/Counters
Timer/Counter
Prescalers
38
ATmega103(L)
The ATmega103(L) provides three general purpose Timer/Counters – two 8-bit T/Cs
and one 16-bit T/C. Timer/Counter0 optionally can be asynchronously clocked from an
external Oscillator. This Oscillator is optimized for use with a 32.768 kHz crystal,
enabling use of Timer/Counter0 as a Real Time Clock (RTC). Timer/Counter0 has its
own prescaler. Timer/Counters 1 and 2 have individual prescaling selection from the
same 10-bit prescaling timer. These Timer/Counters can either be used as a Timer with
an internal clock time base or as a counter with an external pin connection that triggers
the counting.
Figure 28. Prescaler for Timer/Counter1 and Timer/Counter2
For Timer/Counters 1 and 2, the four different prescaled selections are: CK/8, CK/64,
CK/256 and CK/1024, where CK is the CPU clock. Observe that CPU clock frequency
can be lower than the XTAL frequency if the XTAL divider is enabled. For
Timer/Counters 1 and 2, added selections as CK, external source and stop can be
selected as clock sources.
Figure 29. The Timer/Counter0 Prescaler
T1
T2
CS20
CS21
CS22
CK
TOSC1
CS00
CS01
CS02
AS0
CK
TIMER/COUNTER2 CLOCK SOURCE
0
PCK0
TCK2
TIMER/COUNTER0 CLOCK SOURCE
10-BIT T/C PRESCALER
10-BIT T/C PRESCALER
PCK0
CS10
CS12
CS11
TIMER/COUNTER1 CLOCK SOURCE
0
TCK1
0945I–AVR–02/07