ATMEGA64-16AI Atmel, ATMEGA64-16AI Datasheet - Page 117

• Manufacturer Part Number: ATMEGA64-16AI
• Description: IC AVR MCU 64K 16MHZ IND 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA64-16AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4.5 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

Reusing the
Temporary High Byte
Register
Timer/Counter
Clock Sources
Counter Unit
2490Q–AVR–06/10
The following code examples show how to do an atomic write of the TCNTn Register contents.
Writing any of the OCRnA/B/C or ICRn Registers can be done by using the same principle.
Note:
If writing to more than one 16-bit register where the high byte is the same for all registers written,
then the high byte only needs to be written once. However, note that the same rule of atomic
operation described previously also applies in this case.
The Timer/Counter can be clocked by an internal or an external clock source. The clock source
is selected by the Clock Select logic which is controlled by the Clock Select (CSn2:0) bits
located in the Timer/Counter Control Register B (TCCRnB). For details on clock sources and
prescaler, see
The main part of the 16-bit Timer/Counter is the programmable 16-bit bi-directional counter unit.
Figure 47
Assembly Code Example
C Code Example
TIM16_WriteTCNTn:
void TIM16_WriteTCNTn( unsigned int i )
{
}
; Save global interrupt flag
in
; Disable interrupts
cli
; Set TCNTn to r17:r16
out TCNTnH,r17
out TCNTnL,r16
; Restore global interrupt flag
out SREG,r18
ret
unsigned char sreg;
unsigned int i;
/* Save global interrupt flag */
sreg = SREG;
/* Disable interrupts */
_CLI();
/* Set TCNTn to i */
TCNTn = i;
/* Restore global interrupt flag */
SREG = sreg;
1. See “About Code Examples” on page 9.
shows a block diagram of the counter and its surroundings.
r18,SREG
The assembly code example requires that the r17:r16 register pair contains the value to be
written to TCNTn.
“Timer/Counter3, Timer/Counter2 and Timer/Counter1 Prescalers” on page
(1)
(1)
ATmega64(L)
144.
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