ATMEGA644A-MU Atmel, ATMEGA644A-MU Datasheet - Page 117
ATMEGA644A-MU
Manufacturer Part Number
ATMEGA644A-MU
Description
IC MCU AVR 64K FLASH 44VQFN
Manufacturer
Atmel
Series
AVR® ATmegar
Specifications of ATMEGA644A-MU
Core Processor
AVR
Core Size
8-Bit
Speed
20MHz
Connectivity
I²C, SPI, UART/USART
Peripherals
Brown-out Detect/Reset, POR, PWM, WDT
Number Of I /o
32
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)
1.8 V ~ 5.5 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
44-VQFN Exposed Pad
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
- Current page: 117 of 581
- Download datasheet (27Mb)
15.3.1
15.4
8272A–AVR–01/10
Timer/Counter Clock Sources
Reusing the Temporary High Byte Register
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:
The assembly code example requires that the r17:r16 register pair contains the value to be writ-
ten to TCNTn.
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
164A/164PA/324A/324PA/644A/644PA/1284/1284P
Assembly Code Example
C Code Example
TIM16_WriteTCNTn:
void TIM16_WriteTCNTn( unsigned int i )
{
}
; Save global interrupt flag
in r18,SREG
; 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. The example code assumes that the part specific header file is included.
For I/O Registers located in extended I/O map, “IN”, “OUT”, “SBIS”, “SBIC”, “CBI”, and “SBI”
instructions must be replaced with instructions that allow access to extended I/O. Typically
“LDS” and “STS” combined with “SBRS”, “SBRC”, “SBR”, and “CBR”.
”Timer/Counter Prescaler” on page
(1)
(1)
153.
117
Related parts for ATMEGA644A-MU
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
Manufacturer:
Atmel Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
Manufacturer:
ATMEL Corporation
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ 5V 64-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ COM 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ IND 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ COM 64-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64KB FLASH 16MHZ 64TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU AVR 64KB FLASH 16MHZ 64QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC AVR MCU 64K 16MHZ IND 64-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC MCU AVR 64K 5V 16MHZ 64-TQFP
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
IC MCU AVR 64K 5V 16MHZ 64-QFN
Manufacturer:
Atmel
Datasheet:
Part Number:
Description:
MCU 8-Bit ATmega AVR RISC 64KB Flash 5V 64-Pin TQFP T/R
Manufacturer:
Atmel
Datasheet: