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ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller VQFN 32 (5x5) 8-Bit 10 MHz I/O number 23
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23
2545TS–AVR–05/11
ATmega48/88/168
11. Errata
11.1 Errata Atmel ATmega48
The revision letter in this section refers to the revision of the ATmega48 device.
11.1.1 Rev. D
•
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
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).
11.1.2 Rev. C
•
Reading EEPROM when system clock frequency is below 900kHz may not work
• Interrupts may be lost when writing the timer registers in the asynchronous timer
1. Reading EEPROM when system clock frequency is below 900kHz may not work
Reading Data from the EEPROM at system clock frequency below 900kHz may result in
wrong data read.
Problem fix/workaround
Avoid using the EEPROM at clock frequency below 900kHz.
2. 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).
11.1.3 Rev. B
•
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
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).