ATMEGA168-20PI Atmel, ATMEGA168-20PI Datasheet - Page 356

• Manufacturer Part Number: ATMEGA168-20PI
• Description: IC AVR MCU 16K 20MHZ 28DIP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA168-20PI

• 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: 23
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

34. Errata
34.1
34.1.1
34.1.2
34.1.3
356
Errata ATmega48
ATmega48/88/168
Rev. D
Rev. C
Rev. B
The revision letter in this section refers to the revision of the ATmega48 device.
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1. Interrupts may be lost when writing the timer registers in the asynchronous timer
•
•
1.
2. Interrupts may be lost when writing the timer registers in the asynchronous timer
•
1. Interrupts may be lost when writing the timer registers in the asynchronous timer
Interrupts may be lost when writing the timer registers in the asynchronous timer
Reading EEPROM when system clock frequency is below 900 kHz may not work
Interrupts may be lost when writing the timer registers in the asynchronous timer
Interrupts may be lost when writing the timer registers in the asynchronous timer
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
Reading EEPROM when system clock frequency is below 900 kHz may not work
Reading Data from the EEPROM at system clock frequency below 900 kHz may result in
wrong data read.
Problem Fix/Workaround
Avoid using the EEPROM at clock frequency below 900 kHz.
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
The interrupt will be lost if a timer register that is synchronous timer clock is written when the
asynchronous Timer/Counter register (TCNTx) is 0x00.
Problem Fix/Workaround
Always check that the asynchronous Timer/Counter register neither have the value 0xFF nor
0x00 before writing to the asynchronous Timer Control Register (TCCRx), asynchronous
Timer Counter Register (TCNTx), or asynchronous Output Compare Register (OCRx).
2545S–AVR–07/10