ATTINY461-15MZ Atmel, ATTINY461-15MZ Datasheet - Page 89

• Manufacturer Part Number: ATTINY461-15MZ
• Description: MCU AVR 4K FLASH 15MHZ 32-QFN
• Manufacturer: Atmel
• Series: AVR® ATtinyr

Specifications of ATTINY461-15MZ

• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Speed: 16MHz
• Number Of I /o: 16
• Eeprom Size: 256 x 8
• Core Processor: AVR
• Program Memory Type: FLASH
• Ram Size: 256 x 8
• Program Memory Size: 4KB (4K x 8)
• Data Converters: A/D 11x10b
• Oscillator Type: Internal
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Connectivity: USI
• Core Size: 8-Bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

15. Timer/Counter1 Prescaler
15.0.1
15.0.2
7753F–AVR–01/11
Prescaler Reset
Prescaler Initialization for Asynchronous Mode
Figure 15-1
nous clocking mode and an asynchronous clocking mode. The synchronous clocking mode uses
the system clock (CK) as a clock timebase and asynchronous mode uses the fast peripheral
clock (PCK) as a clock time base. The PCKE bit from the PLLCSR register enables the asyn-
chronous mode when it is set (‘1’).
Figure 15-1. Timer/Counter1 Prescaler
In the asynchronous clocking mode the clock selections are from PCK to PCK/16384 and stop,
and in the synchronous clocking mode the clock selections are from CK to CK/16384 and stop.
The clock options are described in
ister, TCCR1B.
The frequency of the fast peripheral clock is 64 MHz or 32 MHz in Low Speed mode (the LSM bit
in PLLCSR register is set to one). The Low Speed Mode is recommended to use when the sup-
ply voltage below 2.7 volts are used.
Setting the PSR1 bit in TCCR1B register resets the prescaler. It is possible to use the Prescaler
Reset for synchronizing the Timer/Counter to program execution.
To change Timer/Counter1 to the asynchronous mode follow the procedure below:
1. Enable PLL.
2. Wait 100 µs for PLL to stabilize.
3. Poll the PLOCK bit until it is set.
4. Set the PCKE bit in the PLLCSR register which enables the asynchronous mode.
CK
PCKE
PCK 64/32 MHz
shows the Timer/Counter1 prescaler that supports two clocking modes, a synchro-
CS10
CS11
CS12
CS13
S
A
PSR1
T1CK
0
Table 15-1 on page 91
ATtiny261/ATtiny461/ATtiny861
TIMER/COUNTER1 COUNT ENABLE
T/C PRESCALER
14-BIT
and the Timer/Counter1 Control Reg-
89