atmega103 ATMEL Corporation, atmega103 Datasheet - Page 42

• Manufacturer Part Number: atmega103
• Description: Atmega103 8-bit With 128k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

Timer/Counter0 – TCNT0
Timer/Counter2 – TCNT2
42
ATmega103(L)
In PWM mode, this bit has no effect.
• Bits 2, 1, 0 – CS02, CS01, CS00/CS22, CS21, CS20: Clock Select Bits 2, 1 and 0
The Clock Select2 bits 2, 1 and 0 define the prescaling source of the Timer/Counter.
Table 11. Timer/Counter0 Prescale Select
Table 12. Timer/Counter2 Prescale Select
The Stop condition provides a Timer Enable/Disable function. The CK down divided
modes are scaled directly from the CK CPU clock. If the external pin modes are used for
Timer/Counter2, transitions on PD7/(T2) will clock the counter even if the pin is config-
ured as an output. This feature can give the user software control of the counting.
Bit
$32 ($42)
Read/Write
Initial Value
Bit
$24 ($44)
Read/Write
Initial Value
CS02
CS22
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
CS01
CS21
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
MSB
MSB
R/W
R/W
7
0
7
0
CS00
CS20
R/W
R/W
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
6
0
6
0
Description
Timer/Counter0 is stopped.
PCK0
PCK0/8
PCK0/32
PCK0/64
PCK0/128
PCK0/256
PCK0/1024
Description
Timer/Counter2 is stopped.
CK
CK/8
CK/64
CK/256
CK/1024
External Pin PD7(T2), falling edge
External Pin PD7(T2), rising edge
R/W
R/W
5
0
5
0
R/W
R/W
4
0
4
0
R/W
R/W
3
0
3
0
R/W
R/W
2
0
2
0
R/W
R/W
1
0
1
0
LSB
R/W
LSB
R/W
0
0
0
0
0945I–AVR–02/07
TCNT0
TCNT2