ATMEGA16-16AUR Atmel, ATMEGA16-16AUR Datasheet - Page 22

• Manufacturer Part Number: ATMEGA16-16AUR
• Description: MCU AVR 128KB FLASH 16MHZ 44TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA16-16AUR

• 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: 32
• Program Memory Size: 16KB (8K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 1K 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: 44-TQFP, 44-VQFP
• For Use With: ATSTK600-TQFP44 - STK600 SOCKET/ADAPTER 44-TQFPATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

EEPROM Write During
Power-down Sleep
Mode
Preventing EEPROM
Corruption
2466T–AVR–07/10
The next code examples show assembly and C functions for reading the EEPROM. The exam-
ples assume that interrupts are controlled so that no interrupts will occur during execution of
these functions.
When entering Power-down Sleep mode while an EEPROM write operation is active, the
EEPROM write operation will continue, and will complete before the Write Access time has
passed. However, when the write operation is completed, the Oscillator continues running, and
as a consequence, the device does not enter Power-down entirely. It is therefore recommended
to verify that the EEPROM write operation is completed before entering Power-down.
During periods of low V
too low for the CPU and the EEPROM to operate properly. These issues are the same as for
board level systems using EEPROM, and the same design solutions should be applied.
An EEPROM data corruption can be caused by two situations when the voltage is too low. First,
a regular write sequence to the EEPROM requires a minimum voltage to operate correctly. Sec-
ondly, the CPU itself can execute instructions incorrectly, if the supply voltage is too low.
Assembly Code Example
C Code Example
EEPROM_read:
unsigned char EEPROM_read(unsigned int uiAddress)
{
}
; Wait for completion of previous write
sbic EECR,EEWE
rjmp EEPROM_read
; Set up address (r18:r17) in address register
out
out
; Start eeprom read by writing EERE
sbi
; Read data from data register
in
ret
/* Wait for completion of previous write */
while(EECR & (1<<EEWE))
/* Set up address register */
EEAR = uiAddress;
/* Start eeprom read by writing EERE */
EECR |= (1<<EERE);
/* Return data from data register */
return EEDR;
;
EEARH, r18
EEARL, r17
EECR,EERE
r16,EEDR
CC,
the EEPROM data can be corrupted because the supply voltage is
ATmega16(L)
22