attiny24v ATMEL Corporation, attiny24v Datasheet - Page 116

• Manufacturer Part Number: attiny24v
• Description: 8-bit Avr Microcontroller With 2/4/8k Bytes Insystem Programmable Flash
• Manufacturer: ATMEL Corporation

13.3
13.3.1
116
Register Description
ATtiny24/44/84
GTCCR – General Timer/Counter Control Register
quency (Nyquist sampling theorem). However, due to variation of the system clock frequency
and duty cycle caused by Oscillator source (crystal, resonator, and capacitors) tolerances, it is
recommended that maximum frequency of an external clock source is less than f
An external clock source can not be prescaled.
Figure 13-2. Prescaler for Timer/Counter0
Note:
• Bit 7 – TSM: Timer/Counter Synchronization Mode
Writing the TSM bit to one activates the Timer/Counter Synchronization mode. In this mode, the
value that is written to the PSR10 bit is kept, hence keeping the Prescaler Reset signal asserted.
This ensures that the Timer/Counter is halted and can be configured without the risk of advanc-
ing during configuration. When the TSM bit is written to zero, the PSR10 bit is cleared by
hardware, and the Timer/Counter start counting.
• Bit 0 – PSR10: Prescaler 0 Reset Timer/Counter n
When this bit is one, the Timer/Countern prescaler will be Reset. This bit is normally cleared
immediately by hardware, except if the TSM bit is set.
PSR10
clk
Bit
0x23 (0x43)
Read/Write
Initial Value
T0
I/O
1. The synchronization logic on the input pins (
Synchronization
TSM
R/W
7
0
R
6
–
0
Clear
R
5
–
0
R
4
–
0
T0)
is shown in
R
3
–
0
R
2
–
0
Figure 13-1 on page
clk
T0
R
1
–
0
PSR10
clk_I/O
R/W
0
0
8006H–AVR–10/09
115.
/2.5.
GTCCR